If you want to have smaller segments you can do something like this: 1. Create audiences for 10 days, 20 days, 30 days, etc. 2. Set targeting in different ad groups like this AG1: Target only 10 day list AG2: Target 20 day list but exclude 10 day list AG3: Target 30 day list buy exclude 20 day list This way you'll see how people convert over time in different periods and you can also experiment with different ads in different periods.