Log in and go to the Shopify admin analytics dashboard. Right there is a metrics that is both a) the most obsessed over number, and b) the least uselful number in conversion rate optimization.

Shopify calculates CVR by Orders and Session.

Conversion Rate = (Total Orders / Total Sessions) x 100

This is oversimplified on purpose. Shopify cannot afford confusion in the analytics dashboard. They need to have a standardized number that fits every merchant from every industry.

This works fairly well as a barometer. It shows the overall health of the store and traffic quality. But the data is an agreggate, and there is no native way to decontruct the data to find real insights for optimization.

Mouse Whisperer calculates CVR for action

• by Product - shows you which products need CRO and which don’t.
• by Traffic Source - breaks down Product CVR by marketing channel, showing where you marketing money is actually driving sales.
• by Snapshot - when you need to know if a change is working or not, snapshots give you the CVR of a specified cohort.

There is nothing wrong with an overall CVR as a barometer, but there is something wrong with using that number to meaure the effect of your CRO work.