Skip to content

2. Strategic Negotiation & Objection Handling

Listen Audio 🎧

Audio Version - Listen to this module on-the-go. Perfect for commutes or multitasking. Duration: 17:15 minutes

Strategic Negotiation and Objection Handling
17:15

 

What You'll Learn (Audio Version)

  • How to segment accounts by tier (high-touch, mid-touch, low-touch) and allocate CSM time strategically based on ARR and impact
  • The Eisenhower Matrix for CSMs: prioritizing urgent vs. important tasks to focus 70% of time on high-value strategic activities
  • Industry data showing average CSM manages 60-100 accounts and 41% miss expansion opportunities due to poor time management
  • Time-blocking techniques including meeting-free days, batching similar tasks, and setting email SLAs to avoid burnout
  • Automation strategies that reduce CSM workload by 25% through self-service portals, automated reports, and CRM triggers
  • Setting clear boundaries to prevent burnout: avoiding instant email responses, saying no to low-priority requests, and protecting deep work time

Watch Video 📹

Video Version - Watch the complete video tutorial with visual examples and demonstrations. Duration: 7:47 minutes

Read Article 📖

Learning Objectives:

  • Master frameworks for handling common objections related to pricing, features, and ROI
  • Apply strategic negotiation techniques for renewals, upsells, and contract discussions
  • Use data-driven justifications to strengthen your position in value conversations
  • Balance customer advocacy with business objectives in negotiation scenarios
  • Implement the Give & Get approach to create mutual value exchanges
  • Navigate pricing objections using value-based framing instead of defensive responses

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Introduction

Customer Success Managers frequently encounter objections related to pricing, product limitations, contract terms, or ROI concerns. With SaaS customers increasingly reevaluating vendors before renewal, mastering negotiation ensures that customers remain engaged, satisfied, and aligned with both business objectives and financial expectations.

Negotiation isn't about "winning" - it's about finding solutions where both customer and company succeed. The best CSMs position objections as opportunities to deepen relationships and demonstrate value.

The Cost of Poor Negotiation Skills

Without strategic negotiation and objection handling capabilities, CSMs may:

  • Lose winnable renewals by defaulting to price discounts instead of demonstrating value
  • Give away margin unnecessarily without receiving anything in return (testimonials, case studies, commitments)
  • Fail to address underlying concerns, allowing small objections to compound into churn
  • Damage relationships by being defensive or dismissive when customers raise legitimate concerns
  • Miss expansion opportunities hidden within objection conversations
  • Create unsustainable deals (steep discounts, unfavorable terms) that hurt long-term business viability

The Benefits of Mastering Strategic Negotiation

Effective negotiation and objection handling enables you to:

  • Achieve 20-30% higher renewal rates by focusing on value-driven conversations instead of price defenses
  • Reduce revenue leakage by 12-18% through cross-functional alignment with Sales and Finance on deal strategies
  • Turn objections into deeper discovery opportunities that reveal upsell and expansion paths
  • Build stronger relationships by addressing concerns authentically rather than avoiding difficult topics
  • Create sustainable agreements that benefit both customer and company long-term
  • Position yourself as strategic partner who understands business realities and finds creative solutions

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

PART 1: HANDLING INITIAL OBJECTIONS

Customers often push back not because they don't want the product, but because they haven't yet realized its full value or have legitimate concerns that need addressing.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Industry Context: The Re-Evaluation Trend

Current SaaS Market Dynamics:

  • 50% of SaaS customers reconsider their vendors before renewal, emphasizing need for proactive negotiation strategies ChurnZero 
  • 20-30% higher renewal rates for CSMs who focus on value-driven conversations rather than price-based defenses ChurnZero 
  • 41% of SaaS companies now implementing usage-based pricing, requiring more strategic negotiations to meet customer expectations ChurnZero 
  • 15-20% higher retention rates for companies that support renewals with performance metrics and data ChurnZero 
  • 12-18% reduction in revenue leakage when CSMs collaborate with Finance and Sales on negotiation strategies ChurnZero 

What This Means for CSMs:

  • More customers are actively evaluating alternatives before renewals
  • Price alone won't retain customers - demonstrated value drives decisions
  • Flexibility in pricing models requires CSMs to understand value-based selling
  • Data and metrics are essential ammunition for renewal conversations
  • Cross-functional alignment (CS + Sales + Finance) is critical for optimal outcomes

💡 Pro Tip: Track which customers are most likely to re-evaluate vendors by monitoring: contract coming up in 90 days, recent budget discussions, competitor mentions, declining engagement, or industry-wide cost-cutting trends. Proactively address renewal value 120 days early, not 30 days reactively.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Turning "No" into "Not Yet"

The goal is to shift resistance into an opportunity for further discussion and discovery.

Step 1: Clarify the Concern

Don't assume you know why customer is objecting. Ask open-ended questions to understand root cause:

Effective clarifying questions:

  • "Can you help me understand what's behind your hesitation?"
  • "What specifically would need to change for this to work for you?"
  • "Is this about the price itself, or about the value you're seeing relative to cost?"
  • "When you say it's too expensive, what are you comparing it to?"
  • "What's driving the need to reconsider right now?"

Why this works:

  • Often the stated objection isn't the real issue
  • Asking shows you care about understanding, not just closing
  • Opens dialogue that reveals the actual barrier
  • Prevents wasting time solving the wrong problem

Example:
Customer: "This is too expensive."

Poor response: "Let me see if I can get you a discount." [Assumes price is real issue]

Good response: "I understand budget is a concern. Help me understand - is this about the total investment amount, the payment terms, or whether you're seeing enough value to justify the cost?" [Diagnoses real issue]

Step 2: Empathize & Validate

Acknowledge their concern as legitimate before addressing it:

Validation phrases:

  • "I completely understand why that would be a concern. Many of our customers felt the same way before..."
  • "That's a fair point - budget decisions are never easy, especially in the current market."
  • "I appreciate you being direct about this. Let's explore options together."
  • "You're right to question whether the investment is justified. Let me show you the data."

Why validation matters:

  • Disarms defensiveness and builds rapport
  • Shows you're on their side, not just company's side
  • Creates psychological safety for honest conversation
  • Positions you as partner, not adversary

Example:
Customer: "We're not sure we're getting enough value to justify renewal."

Validation: "I completely understand - you need to see clear ROI for every investment, especially in this market. That's exactly the right question to ask. Let me show you the value you've achieved so far and where there's opportunity to increase it further."

Step 3: Reframe with Value-Based Framing

Shift focus from cost to business impact and ROI:

Instead of defending price, connect cost to measurable outcomes:

Price Objection Example:

Customer: "Your competitor offers similar functionality for 30% less."

Poor response: "But we have better customer support!" [Generic, unquantified]

Strong response: "I understand the price comparison. Let me share what differentiates us beyond features: Based on your current usage, you've saved 240 hours this quarter through our automation - that's $12,000 in labor cost savings at your team's rates. When you factor in implementation time with a new vendor (typically 3-4 months), migration costs ($15-20k), and productivity loss during transition, what looks like 30% savings often becomes a net cost increase. Can we review your actual ROI together?"

Feature Gap Objection Example:

Customer: "We need [Feature X] that you don't have."

Reframe: "I understand [Feature X] is important for your workflow. While we don't have that exact functionality, our customers achieve the same outcome using [Alternative Approach]. Let me show you how [Similar Company] solved this exact problem. Would that approach work for you?"

💡 Pro Tip: Create a "Value Reframe Library" for common objections. For each objection, document: The reframe, supporting data/metrics, customer example, and alternative solutions. Practice these reframes until they're natural, not scripted.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Best Practices for Handling Initial Objections

  • Never assume the stated objection is the real issue → Ask clarifying questions to understand root cause before responding
  • Validate before reframing → "That's a fair concern" creates psychological safety for honest dialogue
  • Use the 3-step framework → Clarify, Empathize, Reframe with value-based framing every time
  • Quantify value in customer's terms → Calculate ROI using their labor costs, time savings, and business outcomes
  • Compare total cost of switching → Include implementation time, migration costs, productivity loss, and learning curve
  • Provide proof points → Share similar customer examples, case studies, and benchmark data
  • Address objections proactively → In renewal conversations, surface potential concerns yourself before customer raises them

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

PART 2: NEGOTIATING RENEWALS, UPSELLS & COMMITMENTS

With 41% of SaaS companies adopting usage-based pricing, customers have more flexibility in renewal decisions. CSMs must negotiate strategically rather than relying on rigid contract structures.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

The Give & Get Approach (Mutual Value Exchange)

Instead of offering discounts or concessions outright, create mutual value exchanges where both parties benefit.

How Give & Get Works

Principle: Every concession you make should be exchanged for something that benefits your business.

Common Give & Get Scenarios:

Scenario 1: Discount Request

Customer asks: "Can you give us 20% off?"

Give & Get Response:
"We can explore pricing flexibility if you're willing to commit to an annual contract instead of quarterly renewal. This gives us revenue predictability and gives you locked-in pricing for 12 months. Would that work?"

Alternatives to give:

  • Longer contract commitment (1 year → 3 years)
  • Case study participation or testimonial
  • Reference customer availability for sales calls
  • User conference speaking opportunity
  • Beta testing participation for new features

Scenario 2: Payment Terms

Customer asks: "Can we pay monthly instead of annual upfront?"

Give & Get Response:
"We can definitely offer monthly billing. However, our annual upfront customers receive priority support and early access to new features. Would you value those benefits enough to consider quarterly payments as a middle ground?"

Scenario 3: Feature Request

Customer asks: "Can you prioritize [Feature X] on your roadmap?"

Give & Get Response:
"I can advocate strongly for this feature with Product if you're willing to participate in the beta testing program and provide detailed feedback. This ensures the feature actually solves your use case. Would you commit 5-10 hours for that?"

💡 Pro Tip: Never give discounts as first response to pricing objections. Exhaust value demonstration, payment flexibility, and other creative solutions first. Reserve discounting as last resort and ALWAYS get something in return (multi-year commitment, case study, expansion).

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Anchoring Technique (Setting Expectations)

Present higher-value options first to make standard offerings seem more reasonable by comparison.

How Anchoring Works

Psychological principle: First number mentioned in negotiation becomes reference point (anchor) that influences perception of subsequent offers.

Application in CSM conversations:

Example 1: Renewal Conversation

Without Anchoring (Weak):
"Your renewal is $100k. Should we proceed?"

With Anchoring (Strong):
"Based on your growth and success this year, most customers in your segment are upgrading to our Enterprise plan at $150k for the advanced features you've been requesting. However, I can also present options at your current tier ($100k) or a mid-tier option at $125k with some of those capabilities. Which aligns best with your goals?"

Effect: $100k now seems like a deal compared to $150k anchor.

Example 2: Upsell Discussion

Without Anchoring:
"Would you like to add Feature X for $20k?"

With Anchoring:
"Companies achieving the outcomes you mentioned typically invest in our Premium package ($50k) which includes Feature X plus automation capabilities. We also have a mid-tier option ($35k) with Feature X and reporting, or we can add just Feature X ($20k) if you want to start there. What makes most sense for your team?"

Effect: $20k option seems modest compared to $50k anchor.

💡 Pro Tip: When using anchoring, always present the high option as genuinely valuable, not artificially inflated. Explain WHY most customers choose that tier (more ROI, faster outcomes, better support). If anchor seems manipulative rather than informative, it backfires.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Data-Driven Justifications

Use product usage reports, performance benchmarks, and ROI calculations to strengthen your negotiation position.

Building Data-Backed Renewal Cases

Components of strong data justification:

1. Usage Analytics

  • "Your team logged 1,250 sessions this quarter, 40% higher than Q1"
  • "Feature X adoption increased from 30% to 75% of your users"
  • "You're utilizing 8 of our 10 core modules effectively"

2. Business Outcomes

  • "This resulted in 25% reduction in manual workflows (120 hours saved monthly)"
  • "Your customer response time improved from 48 hours to 6 hours"
  • "You've processed 15,000 transactions through our automation vs. 3,000 manually before"

3. ROI Calculation

  • "At your team's labor rate ($50/hour), 120 hours saved monthly = $72,000 annual value"
  • "Compare this to your annual investment of $50,000 = 144% ROI"
  • "Your payback period was 4.2 months, and you've been realizing value for 8 months since"

4. Peer Benchmarking

  • "Similar companies in your industry average 60% feature adoption - you're at 75%"
  • "Your NPS score (68) is 15 points higher than our customer average"
  • "Comparable accounts see $X value - you're tracking at $Y, which is above average"

Example Renewal Presentation:

"Let me share the value you've achieved this year: Your team saved 1,440 hours through automation (worth $72k at your rates), improved response times by 87%, and increased customer satisfaction by 23%. Your total investment was $50k, representing 144% ROI. Based on industry benchmarks, you're in the top 25% of users by adoption and outcomes. Given this performance, I recommend renewing at current tier with option to add [Premium Feature] as you continue scaling."

Industry Insight:
SaaS companies that justify renewals with performance metrics see 15-20% higher retention rates than those negotiating purely on price (ZAPSCALE, 2024)

💡 Pro Tip: Create renewal ROI presentations 60 days before contract ends, not during the renewal call. Send it ahead of time so customers come to the conversation already seeing value, not defending budget. This shifts the conversation from "should we renew?" to "how should we expand?"

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Best Practices for Strategic Renewal Negotiations

  • Use the Give & Get approach → Exchange concessions (discounts, payment terms) for valuable commitments (multi-year, case studies, referrals)
  • Apply anchoring strategically → Present premium option first to make standard pricing seem reasonable by comparison
  • Build data-driven justification → Prepare usage analytics, ROI calculations, and peer benchmarks 60 days before renewal
  • Quantify in customer's metrics → Calculate value in their labor costs, time saved, and business outcomes, not generic claims
  • Compare total cost of alternatives → Include switching costs (implementation, migration, productivity loss) in pricing discussions
  • Start renewal conversations early → 90-120 days before contract end to address concerns proactively
  • Coordinate with Sales and Finance → Align on discount approval limits, payment term options, and expansion opportunities before customer conversations

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

PART 3: BALANCING CUSTOMER ADVOCACY WITH BUSINESS OBJECTIVES

A CSM's role is not to agree to all customer demands, but to balance advocacy with sustainable business practices that benefit both parties long-term.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Know Your Limits: What's Negotiable vs. What's Not

Be clear on boundaries for pricing, contract flexibility, and feature requests before entering negotiations.

Creating Your Negotiation Boundaries

Work with leadership to establish:

Pricing Flexibility:

  • Maximum discount available without approval: ____%
  • Discount in exchange for multi-year commitment: ____%
  • Payment term options (monthly, quarterly, annual)
  • Volume/seat discounts at what thresholds
  • When to escalate to manager for approval

Contract Terms:

  • Early termination clauses (30/60/90 day notice?)
  • Auto-renewal vs. explicit renewal required
  • Price increase caps for subsequent years
  • Downgrade policies and limitations

Feature Requests:

  • When to promise roadmap features vs. set expectations
  • How to communicate "not available" without killing deal
  • Workaround options you can offer immediately
  • Beta program participation criteria

What You CAN Negotiate:

Example: "While we can't adjust the base pricing, I CAN offer: customized training sessions to increase your ROI, flexible payment terms to ease cash flow, or early access to beta features if you commit to annual renewal."

What You CANNOT Negotiate:

Example: "Our pricing reflects the value we deliver and investment in the product. What I CAN'T do is discount below our standard rates, but what I CAN do is ensure you're getting maximum value from every dollar spent. Let's review your usage to optimize your investment."

💡 Pro Tip: Create a one-page "Negotiation Authority Matrix" showing what you can approve independently vs. what needs manager approval vs. what's absolutely off-limits. Share this with your manager to ensure alignment and prevent making promises you can't keep.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Internal Alignment: Coordinating with Sales & Finance

Work closely with Sales and Finance teams to ensure CSM-negotiated deals align with company profitability goals.

Creating Cross-Functional Negotiation Alignment

Before renewal conversations:

Align with Sales:

  • What's the expansion opportunity potential?
  • Are they targeting this account for upsell this quarter?
  • What pricing flexibility exists for multi-year deals?
  • Should AE join renewal conversation for expansion discussion?

Align with Finance:

  • What discount levels are approved for this customer segment?
  • Are there payment term options available?
  • How does this renewal impact quarterly NRR targets?
  • Any company-wide pricing changes coming that affect this deal?

Document internally:

  • Create shared renewal tracker visible to CS, Sales, Finance
  • Flag high-risk renewals 120 days early for collaborative planning
  • Document agreed-upon negotiation strategy before customer conversation
  • Debrief after renewal to capture learnings

Example:
Before negotiating a $200k renewal, CSM coordinates with Sales (identified $50k expansion opportunity) and Finance (approved 10% discount for 2-year commit). CSM enters conversation with: "Here's our ROI, here's expansion opportunity that adds value, and if you commit to 2 years we can offer favorable pricing." Result: Customer renews at $220k for 2 years instead of negotiating down on 1-year deal.

Industry Insight:
CSMs collaborating with Finance and Sales on negotiation strategies reduce revenue leakage by 12-18% (ARdigital, 2024).

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Long-Term Mindset: Sustainable Agreements

Prioritize sustainable agreements over short-term wins that create long-term problems.

What "Sustainable" Means

Unsustainable deal examples:

  • 40% discount with no corresponding commitment - sets bad precedent
  • Promises of features that aren't on roadmap - creates future disappointment
  • Payment terms that strain company cash flow - may affect service quality
  • Contract clauses that are operationally impossible to fulfill

Sustainable deal examples:

  • 15% discount in exchange for 3-year commitment and case study
  • Monthly payments with slightly higher total to account for payment processing
  • Feature commitment with realistic timeline and beta participation
  • Flexible terms that both parties can actually deliver on

Example of long-term thinking:

Short-term win: Give 30% discount to save renewal this quarter.
Long-term problem: Customer expects same discount next renewal, margin destroyed, sets precedent.

Better approach: "Instead of discounting, let me show you how to increase ROI by 40% through better feature utilization. We can also explore payment flexibility if cash flow is the concern. My goal is creating a sustainable partnership, not just saving this renewal."

💡 Pro Tip: When tempted to give steep discount to save a deal, ask yourself: "Would I want to renew this customer again in 12 months at these terms?" If no, you're creating a future problem. Better to lose an unsustainable customer than set bad precedents.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Best Practices for Balancing Advocacy with Business Goals

  • Know your negotiation boundaries → Understand what you can approve vs. what needs escalation before customer conversations
  • Coordinate with Finance and Sales → Align on renewal strategy, pricing flexibility, and expansion opportunities 30+ days before approaching customer
  • Think long-term sustainability → Avoid concessions that create bad precedents or destroy margins
  • Use Give & Get consistently → Every discount or concession should be exchanged for multi-year commit, case study, or referral
  • Document all negotiations → Track what was approved, by whom, and under what circumstances for future reference
  • Escalate strategically → Know when to involve manager (non-standard terms), Finance (payment issues), or Sales (expansion discussions)
  • Prioritize relationship over single deal → Sometimes losing an unsustainable customer is better than setting dangerous precedents

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

REAL-WORLD APPLICATION

Case Study: Turning $250K Renewal Risk into Multi-Year Commitment

Initial Situation: Budget Pressure and Low Perceived Value

A mid-sized tech company ($250K ARR) was considering switching vendors due to budget constraints and perceived low ROI. The CFO wanted to cut SaaS expenses due to economic downturn pressures, and procurement was evaluating cheaper alternatives.

Challenges Identified:

1. Feature Underutilization
Customer was using only 40% of available features, missing key automation tools that could reduce manual workload by 25%

2. Budget Constraints
CFO mandate to reduce SaaS spending by 15-20% across the board

3. Renewal Risk
Account marked as "high churn risk" requiring immediate intervention 90 days before contract end

CSM's Strategic Negotiation Approach:

Step 1: Data-Backed Value Demonstration (Weeks 1-2)

  • Conducted usage audit identifying automation opportunities
  • Built custom ROI report calculating potential savings:
    • Current state: 40 hours weekly on manual processes
    • With full adoption: 10 hours weekly (75% reduction)
    • Annual value: 30 hours weekly × 52 weeks × $65/hour = $101,400 saved
  • Presented to CFO showing product could SAVE more than it COSTS
  • Positioned as cost-reduction tool, not cost center

Step 2: Addressing Budget with Give & Get (Weeks 3-4)

Instead of offering discount upfront, CSM proposed mutual value exchange:

What CSM Gave:

  • Customized training program (6 sessions over 3 months) to increase feature adoption
  • Tiered payment plan (quarterly vs. annual upfront) easing cash flow concerns
  • Locked-in pricing for 3 years (no increases) vs. annual renegotiation

What Customer Gave:

  • 3-year contract commitment providing revenue predictability
  • Case study participation for finance industry marketing
  • Reference customer availability for CFO-level sales conversations
  • Beta participation for new features on roadmap

Step 3: Securing Long-Term Partnership (Weeks 5-8)

  • Established Quarterly Business Reviews (QBRs) with CFO and COO
  • Created strategic roadmap showing how product supports 3-year business objectives
  • Positioned renewal as partnership extension, not vendor evaluation
  • Introduced customer to peer CFOs at similar companies using platform successfully

Results After 3 Months:

$750K total contract value - Customer renewed for 3-year commitment at $250k annually

60% adoption increase - Feature utilization jumped from 40% to 72% through targeted training

Stronger executive relationship - Secured direct CFO engagement, reinforcing strategic value positioning

Became reference customer - Participated in 2 case studies and 3 prospect calls

Expansion opportunity identified - Additional department showing interest ($75k potential)

CSM promoted to Enterprise CSM - Based on saving renewal and structuring strategic multi-year deal

Key Strategies Used:

  • Demonstrated value in CFO's language (cost savings, ROI, operational efficiency)
  • Applied Give & Get instead of discounting (training + payment flexibility for commitment + case study)
  • Used data extensively (usage analytics, ROI calculations, peer benchmarks)
  • Anchored with premium option before presenting standard renewal
  • Built executive relationship through QBRs focused on business outcomes
  • Positioned as strategic partner solving business problems, not vendor selling product

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

KEY TAKEAWAYS: BEST PRACTICES RECAP

✓ 50% of SaaS customers reconsider vendors before renewal - proactive negotiation starting 90-120 days early prevents churn

✓ Use 3-step objection handling: Clarify the concern, Empathize and validate, Reframe with value-based framing

✓ Never assume stated objection is real issue - ask "help me understand what's behind your hesitation" to diagnose root cause

✓ Apply Give & Get approach consistently - every discount or concession should be exchanged for value (multi-year, case study, referral)

✓ Use anchoring technique by presenting premium option first to make standard pricing seem reasonable

✓ Build data-driven justification with usage analytics, ROI calculations, and peer benchmarks prepared 60 days before renewals

✓ Know your negotiation boundaries - understand what you can approve vs. what needs escalation before customer conversations

✓ Coordinate with Sales and Finance - align on renewal strategy, pricing flexibility, and expansion opportunities pre-customer discussion

✓ Focus on sustainable agreements - avoid concessions that create bad precedents or destroy margins for short-term wins

✓ Quantify value in customer's terms - calculate ROI using their labor costs, time savings, and specific business outcomes

✓ Compare total cost of switching - include implementation time, migration costs, and productivity loss in pricing discussions

✓ Value-driven conversations achieve 20-30% higher renewal rates than defensive price-based discussions