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Post-purchase CX metrics: 12 KPIs with formulas

Post-purchase CX metrics measure how well you serve customers after they buy. This guide lists 12 KPIs with formulas, how to read them together and how Insights and Agent reporting fit in. It is part of our aftersales service guide.

What are post-purchase CX metrics?

Post-purchase CX metrics are measurements of the customer experience after the sale: how quickly and completely questions are solved, how customers feel about it and whether they come back. They connect support work to revenue.

They matter because retention is where aftersales service pays off. Reichheld and Sasser in Harvard Business Review (1990) found that cutting customer defections by 5% raised profits by 25% to 85% in the service businesses they studied, and Harvard Business Review notes a new customer can cost five to 25 times more to win than an existing one costs to keep.

What are the formulas for post-purchase CX metrics?

MetricFormulaWhat it tells you
Resolution rateResolved conversations ÷ total conversations × 100How much demand you actually solve
First contact resolution (FCR)Resolved in first contact ÷ total resolved × 100Whether customers must come back
CSATPositive ratings (4–5 of 5) ÷ total ratings × 100Satisfaction with the interaction
Net Promoter Score (NPS)% promoters (9–10) − % detractors (0–6)Likelihood to recommend
Customer Effort Score (CES)Sum of effort ratings ÷ number of responsesHow easy it was to get help
First response timeSum of time to first reply ÷ conversationsHow fast customers hear back
Time to resolutionSum of time from open to resolved ÷ resolved conversationsHow long problems last
Contact rate per orderConversations ÷ orders × 100Whether problems are prevented
WISMO shareOrder-status conversations ÷ all conversations × 100Delivery communication gaps
Return rateUnits returned ÷ units sold × 100Product and listing fit
Repeat purchase rateCustomers with 2+ orders ÷ total customers × 100Loyalty after the first order
Cost per conversationTotal support cost ÷ conversationsEfficiency of the support operation

Use the same time window and the same definition of “resolved” for every channel and for AI and human conversations.

Which metrics measure support quality?

Resolution rate

The share of conversations fully solved. Define "resolved" strictly: the customer did not reopen or contact you again on the same issue within a set window, such as 72 hours. See resolution rate explained.

First contact resolution (FCR)

The share of resolved conversations that needed only one contact. Low FCR usually means missing data (the agent cannot see the order), missing permissions (the agent cannot refund) or unclear policy.

CSAT

A one-question survey after the conversation. Count 4 and 5 on a 5-point scale as positive. Watch response rates: a 5% response rate says more about who answers than about everyone.

Customer Effort Score

Asks how easy it was to get help. It is especially useful for returns and warranty flows, where effort is the main complaint.

NPS

A relationship metric rather than a support one. Use it to track overall loyalty, and use CSAT and CES to judge individual interactions.

Which metrics measure speed?

First response time and time to resolution. Report medians as well as averages, because a few very old conversations distort the average. Speed without resolution is a trap: a quick first reply that solves nothing lowers FCR and raises volume.

Which metrics connect support to business outcomes?

Contact rate per order

The best single test of whether aftersales problems are being prevented. If orders grow 20% and conversations grow 5%, prevention is working.

WISMO share

High WISMO share points to gaps in delivery communication. See the WISMO guide for fixes.

Return rate

The NRF and Happy Returns 2024 returns report estimated 16.9% of US retail sales would be returned in 2024. Compare your own return rate by product, size and reason, rather than against a single industry average. See returns customer service.

Repeat purchase rate

The share of customers who order again. Compare customers who contacted support with those who did not, and customers whose issue was resolved on first contact with those who needed several. That comparison shows the revenue value of good aftersales service.

Cost per conversation

Total support cost (people, tools, AI fees) divided by conversations. Track it next to resolution rate so cost cuts do not come from solving less.

What should a post-purchase CX dashboard include?

Keep it to one screen with three rows, reviewed weekly.

  1. Quality: resolution rate, FCR, CSAT (split by AI and human).
  2. Speed and cost: median first response time, median time to resolution, cost per conversation.
  3. Business: contact rate per order, WISMO share, return rate, repeat purchase rate.

Below it, list the top five contact reasons this week versus last week and one action per reason. A metric without an owner and an action rarely moves.

See quality across AI and human conversations. Insights detects issues in real time and runs quality monitors.

How do you measure AI in post-purchase support?

Measure AI on resolution, not deflection. Deflection counts a conversation as handled when the customer stops replying, even if they gave up or called instead. Resolution counts only conversations where the problem was solved.

  • Use the same resolved definition for AI and humans.
  • Track AI resolution rate by intent (WISMO, returns, warranty), since some intents automate far better than others.
  • Track CSAT on AI-resolved conversations separately.
  • Track escalation quality: did the person who picked it up have the context they needed?

How Aftersales reports it

Agent is billed at $0.99 per resolution, counted once per conversation, and conversations it cannot help with are free, so the resolution count is also your AI bill. Aftersales customers see a median 71% resolution rate after 90 days. Insights adds real-time issue detection, quality monitors and forecasting across AI and human conversations in Inbox. See pricing for plan details.

What are common mistakes with CX metrics?

  • Counting a conversation as resolved when it was only closed.
  • Using different definitions for AI and human conversations.
  • Reporting averages only, which hide long-tail waits.
  • Chasing CSAT with a low response rate.
  • Tracking support metrics without any business metric next to them.
  • Comparing against generic industry benchmarks instead of your own trend.

Frequently asked questions

What are the most important post-purchase CX metrics?
Resolution rate, first contact resolution, CSAT, time to resolution, contact rate per order, return rate and repeat purchase rate cover quality, speed and business impact.
How do you calculate CSAT?
Divide the number of positive ratings (usually 4 or 5 on a 5-point scale) by total ratings and multiply by 100.
How do you calculate first contact resolution?
Divide the number of issues resolved in the first contact by the total number of resolved issues and multiply by 100.
What is the difference between resolution rate and deflection rate?
Resolution rate counts conversations where the problem was solved. Deflection rate counts conversations that did not reach a human, which can include customers who gave up.
How do you calculate repeat purchase rate?
Divide the number of customers with two or more orders in a period by the total number of customers in that period and multiply by 100.
How do you calculate return rate?
Divide units returned by units sold in the same period and multiply by 100. Some teams also track it by order or by revenue.
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The Aftersales teamCustomer service product specialists

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