The 5 Retention Metrics Every eCommerce Store Should Track

You're tracking revenue. You're tracking conversion rate. You're tracking ROAS on your ads. These are acquisition metrics. They tell you how well you're bringing new people through the door.

But they don't tell you whether those people are coming back.

Most eCommerce brands I talk to can tell me their CAC to the penny but have no idea what their repeat purchase rate is. They know exactly how much they spent on Meta ads last month but couldn't tell you what percentage of last year's customers are still buying.

This is a problem. Because the math is simple: acquiring a new customer costs 5-7x more than retaining an existing one. A 5% increase in retention rate generates a 25-95% increase in profits. The brands with the highest valuations aren't the ones with the best acquisition — they're the ones with the best retention.

Here are the five retention metrics you should be tracking, what good numbers look like, and how to improve each one.

Metric 1: Repeat Purchase Rate

This is the most fundamental retention metric. What percentage of your customers come back and buy again?

How to calculate it: Number of customers who made more than one purchase divided by total number of customers, over a given time period.

What good looks like:

• Below 20%: You have a retention problem. Most customers are one-and-done.
• 20-30%: Average for most eCommerce categories.
• 30-40%: Strong. You're building repeat behavior.
• 40%+: Excellent. Usually only seen in consumable/subscription categories.

The time window matters. A 12-month repeat purchase rate is the standard comparison. But some products have longer purchase cycles (mattresses, furniture) and some have shorter ones (coffee, supplements). Adjust your window to match your product's natural repurchase timeline.

How to improve it:

Post-purchase email sequences that educate, engage, and bring customers back. Not just "here's your tracking number" — actual value. How to use the product. What to pair it with. When to reorder.

Replenishment reminders for consumable products. If your average customer runs out of product in 45 days, send a reminder on day 35. Make reordering easy with a direct link to their last purchase.

Loyalty programs that reward the second and third purchase specifically. Many loyalty programs front-load rewards for the first purchase (welcome discounts) and then wait until the 10th purchase for meaningful rewards. The critical moment is getting the SECOND purchase. Incentivize that transition specifically.

Where to find it in Shopify: Shopify's Customer reports show repeat customer rate. In Klaviyo, create a segment of customers with "Placed Order at least 2 times over all time" and divide by total customers.

Metric 2: Purchase Frequency

How often does the average repeat customer buy from you?

How to calculate it: Total number of orders divided by total number of unique customers, over a given time period.

What good looks like:

• 1.0-1.3: Most customers buy once. You're acquisition-dependent.
• 1.3-1.8: Decent. Some customers are repeating.
• 1.8-2.5: Strong. You've built purchase habits.
• 2.5+: Outstanding. Usually subscription-based or consumable categories.

Why this matters more than repeat purchase rate: A 40% repeat rate with a frequency of 1.4 means your repeat customers buy once more and then stop. A 30% repeat rate with a frequency of 2.5 means fewer customers repeat but the ones who do buy many times. The second scenario is often more valuable because those high-frequency buyers have much higher lifetime value.

How to improve it:

Cross-sell recommendations after purchase. If someone bought a cleanser, the post-purchase flow suggests the toner and moisturizer from the same line. You're creating the next purchase occasion.

Loyalty tiers that reward frequency. "Silver after 2 purchases, Gold after 5, Platinum after 10." Each tier unlocks better perks. The customer is motivated to reach the next tier, which means buying sooner.

Content that creates purchase occasions. A coffee brand that sends a weekly "Brew of the Week" recipe featuring their different blends creates 52 reasons per year to buy a new bag. The content IS the purchase trigger.

New product drops on a regular cadence. If customers know you launch something new every month, they come back to check what's new. Fashion brands are great at this. But any category can apply the "new arrivals" model.

Metric 3: Customer Lifetime Value (LTV)

The total revenue you expect from a customer over their entire relationship with your brand.

How to calculate it (simple version): Average order value multiplied by purchase frequency multiplied by average customer lifespan (in years or months).

Example: $65 AOV times 2.3 purchases per year times 3 years = $448.50 LTV.

What good looks like: This varies wildly by category and price point. The absolute number matters less than the RATIO of LTV to CAC (customer acquisition cost).

• LTV:CAC ratio below 2:1 — You're struggling. It costs too much to acquire customers relative to what they're worth.
• 3:1 — Healthy. For every dollar you spend acquiring, you get three back.
• 4:1 or higher — Strong. You have significant room to invest in growth.

Why LTV trumps everything: A brand with $30 CAC and $120 LTV (4:1 ratio) is in a better position than a brand with $15 CAC and $40 LTV (2.7:1 ratio). The first brand can afford to spend more on acquisition while maintaining profitability. That spending power compounds into market share.

How to improve it:

Increasing AOV (bundles, upsells, premium options) lifts LTV without requiring additional purchases.

Increasing purchase frequency (see above) lifts LTV by extending the relationship.

Extending customer lifespan through retention efforts. If your average customer stays active for 18 months, extending that to 24 months adds 33% to LTV without changing AOV or frequency.

Reducing churn. Every customer you keep from lapsing adds their future purchases to LTV. Winback flows, loyalty programs, and ongoing engagement all fight churn.

Metric 4: Time Between Purchases

The average number of days between a customer's first and second purchase, second and third, etc.

How to calculate it: For each repeat customer, measure the days between consecutive orders. Average across all customers.

Why this metric is overlooked: Most brands track repeat purchase rate as a static number but ignore the TIMING. Knowing that your average customer takes 45 days to make a second purchase gives you an actionable window. You know exactly when to send the replenishment reminder, the loyalty incentive, or the "we miss you" email.

What good looks like: This is entirely dependent on your product category.

• Supplements/consumables: 25-45 days
• Fashion/apparel: 45-90 days
• Beauty/skincare: 30-60 days
• Home goods: 90-180 days
• Electronics: 180-365 days

How to use it:

Map your email flows to this timeline. If the average second purchase happens at day 45, your post-purchase nurture sequence should be building toward a reorder CTA around day 35-40.

Identify customers who are overdue. If someone typically buys every 45 days and it's been 60, they're at risk of lapsing. Trigger a winback or incentive before they forget about you.

Track whether this metric is getting better or worse over time. If time between purchases is shrinking, your retention efforts are working. If it's growing, you're losing engagement.

Where to find it: Klaviyo's predictive analytics include "Expected date of next order" for individual profiles. For aggregate data, export order dates and calculate the average interval in a spreadsheet or analytics tool.

Metric 5: Customer Churn Rate

What percentage of your customers stop buying and are considered "lost"?

How to calculate it: Number of customers who haven't purchased in X days (your defined churn threshold) divided by total active customers at the start of the period.

Defining "churned": This depends on your purchase cycle. If your average customer buys every 45 days, a customer who hasn't bought in 90 days (2x the average cycle) is likely churned. For slower categories (furniture, electronics), your churn threshold might be 12-18 months.

What good looks like:

• Monthly churn above 8%: You're losing customers fast. Acquisition can't keep up.
• Monthly churn 4-8%: Average for most eCommerce. Room to improve.
• Monthly churn below 4%: Strong retention. Your customer base is stable and growing.

Annualized impact: A 5% monthly churn rate means you lose 46% of your customer base in a year. That means nearly half of last year's customers won't buy again this year. You need to replace all of them through acquisition just to stay flat.

How to reduce churn:

Identify the churn moment. At what point in the customer lifecycle do most people lapse? Is it after the first purchase (they never come back)? After the third (they try you, like you, then forget)? The answer tells you where to focus.

Pre-churn intervention. If your data shows customers typically churn at day 90, start your retention efforts at day 60. Don't wait until they're already gone.

Exit surveys and feedback. When someone unsubscribes from your email list or hasn't bought in a while, ask why. You might discover a product quality issue, a shipping problem, or a competitor that's stealing share.

Win-back offers. For customers approaching the churn threshold, a targeted offer can pull them back. But make it conditional — "Come back and here's 15% off your next order" works better than "Here's 15% off" with no urgency.

Putting It All Together: The Retention Dashboard

You need these five metrics visible in one place, updated weekly:

1. Repeat Purchase Rate: Is it trending up or down? (Target: 30%+)
2. Purchase Frequency: Are repeat customers buying more often? (Target: 2.0+)
3. Customer Lifetime Value: Is LTV growing? (Target: 3:1+ LTV:CAC ratio)
4. Time Between Purchases: Is the gap shrinking? (Target: category-specific)
5. Churn Rate: Are you losing fewer customers? (Target: under 5% monthly)

If all five metrics are improving, your business is getting more valuable over time. Each new customer you acquire is worth more, stays longer, and buys more often. That's a compounding machine.

If any metric is declining, that's your priority. Don't throw more money at acquisition to compensate for retention problems. Fix the leak first.

What To Do Right Now

Pull your repeat purchase rate from Shopify's customer reports. That's the single most telling number. If it's below 25%, retention is your biggest growth opportunity — not more ad spend.

Then check your LTV:CAC ratio. If you're spending $50 to acquire a customer worth $80, your margins are razor thin. Either reduce CAC or increase LTV. Retention efforts increase LTV.

If you want help building a retention system — email flows, loyalty strategy, and the analytics to track all five metrics — book a call with our team. We'll show you exactly where retention is leaking and what to do about it.