Using the retention app build a query that looks at the rate of retention for low purchasing users similar to how you did in question 61.
Build a query using the retention app that returns retention for users 8 weeks after their first purchase for users who are in the low purchase bracket. Using the retention app during 8 weeks after each users first ever event with action that matches purchase for user actors with the actor property created in question 39 that matches "low purchasers" show retention on any event. Split by the actor property created in question 60. Starting from the beginning of time to now.
Again the retention app is very powerful in easily putting together retention analysis. In this case were looking at weekly retention, but for users that are in a specific category.
Note: The numbers and result do not need to be an exact match as the data changes over time. The query construction is what is most important. See images below.
*Click to enlarge*