Transactions are grouped in so called transaction groups. The grouping of transactions should help you to get a better and more detailed understanding of your conversion rate.
Transaction are grouped by the customer ID. In case the customer ID is not provided (
NULL) then each transaction is
treated as a separate transaction group.
A transaction group is considered as successful once a transaction is successfully completed.
A transaction group is considered as failed and closed once the last transaction is older than the transaction interval minus the actual time.