The Funnel Based attribution shares a transaction value among all the sessions that led to this transaction and occurred within a preset conversion window.
Let’s look at an example: there were four visits to a website during a period of time, including two sessions with the transactions made on January 10 and January 20. A conversion window is set to 30 days.
According to the Funnel Based attribution, the value of Transaction 1 is attributed to Session 1, 2, and the value of Transaction 2 is attributed to Session 1, 2, 3, 4 (see an image below).
Our example shows that a new transaction doesn't interrupt the preset conversion window.
Therefore, in Funnel Based attribution, once the conversion window is set up (according to the business needs), it stays fixed during the calculations. And the transaction value is attributed to all the earlier sessions within the preset conversion window. If there are several transactions that occurred during this period, a single session might get the value from several transactions. So you’ll see two or more session records with the same ID that hold different values from different transactions.