Attribution models and windows

• Last click: the last ad visit before the order gets the credit.
• First click: the first one does.
• Linear: every visit shares it equally.
• Time decay: recent visits count more; one seven days earlier counts half.
• Position: first and last visits get most, the middle shares the rest.

Windows of 1, 7 and 28 days decide how far back a visit can be and still count. Comparing models side by side shows which channels open a sale and which close it.