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GlossaryUpdated

What is a conversion rate?

A conversion rate is the share of a defined group that completes a goal. In email marketing, the group can be delivered emails, clicks or sessions, and the goal is usually an order. The denominator has to be stated, because the same orders produce different rates against different groups.

Key facts

  • Google Analytics describes conversions as the actions a site owner defines as valuable, such as a purchase. Source
  • Shopify records orders and their totals, which is the outcome an email conversion rate is trying to measure. Source
  • Mailprompt credits revenue on a click with a five-day, last-click window and does not use opens for attribution. Source

What a conversion rate means

This definition is part of the Mailprompt glossary. A conversion rate is a ratio: the number of conversions divided by the number of opportunities. The ratio is only meaningful when both parts are defined.

In email marketing, the opportunity can be a delivered email, a click, a session or a subscriber. The conversion can be an order, a signup or a reply. A report that says the conversion rate is five percent without naming the denominator is not telling you enough to act on.

Choosing the denominator

The denominator should match the question. If you want to know how many recipients bought, divide orders by delivered emails. If you want to know how many people who clicked bought, divide orders by clicks.

Each ratio answers a different question. The delivered-email rate includes the quality of the subject line and the offer. The click rate isolates the landing experience after the click. Neither is more correct; they are different views.

The denominator also affects the noise. A small click group produces a volatile rate. A large delivered group produces a stable but coarse rate. When you compare periods, compare the same denominator.

Conversions and orders

For a store, a conversion is usually a completed order. The order has a total, a currency and a timestamp. A refund or cancellation changes the revenue outcome but does not erase the fact that the order happened.

Google Analytics describes a conversion as an action the site owner defines as valuable. That definition is flexible by design. The flexibility is useful, and it is also why two reports can disagree while both being internally consistent.

Refunds and the report

A refund is a correction, not a separate conversion. If the report counts the original order and ignores the refund, it overstates revenue. If it removes the order, the conversion rate changes retroactively.

The report should state the treatment and apply it consistently. It should also keep the original order and the correction linked, so a refund does not silently move revenue to a different email or a different period.

Using the number

Use conversion rate with click-through rate and attributed revenue. A high conversion rate on a small click group can be a sign of a highly targeted message. A low conversion rate on a large delivered group can be a sign of a broad offer. Neither is a verdict on its own.

Compare like with like. A seasonal campaign, a new list and a changed checkout flow all move the rate for reasons that are not the email. The useful comparison is against a control period or a holdout, not against a different audience.

Frequently asked questions

Is email conversion rate the same as site conversion rate?

No. The denominators differ. A site conversion rate usually divides orders by sessions. An email conversion rate can divide orders by delivered emails or by clicks. The same orders can produce a high rate against a small click group and a low rate against a large delivered group.

What counts as a conversion?

The goal you define. For a store, it is usually a completed order. For a newsletter, it might be a signup or a reply. The definition has to be stable across the comparison, or the rate is not measuring the same thing from period to period.

How do refunds affect conversion rate?

A refunded order was still a conversion at the time it happened. If the report counts refunded orders as conversions, the rate overstates the revenue outcome. If it removes them, the rate falls after the refund. The report should state which treatment it uses and keep it consistent.

Sources