Hey there 👋 Is there any way to put a cap on the number of users enrolled in an AB? It doesn’t have to happen automatically, but I wonder if I see that there are x total users in the test, if I can stop new users from being included in the test, but continuing serving variations to and tracking the activity of the ones who are enrolled?

Hi Christina, thanks for reaching out! Let me double check with the team about this and I'll send an update here as soon as I can.

Thanks for confirming! We’ve been evaluating different tools for running experiments, and I’m mostly just looking to document any limitations so my team can compare to other solutions. We’ve been super impressed by GrowthBook so far 👏 An example might be: I have a three variations of a button that creates a new “project”. Users on a free plan can only create 1 project, so this button will either look normal (control), have a lock icon on it, or appear disabled. Being upfront about the cap on projects could either positively or negatively impact a user’s decision to subscribe by the time they are ready to move on to their second project. The idea is that we could show the variation to a certain number of users and then watch how that subset of users behave for awhile. Sort of like a slow rollout, but we’d use a hard number instead of a percentage, just in case the impact isn’t obvious right away. Alternatively, we might set up a new targeting condition to limit based on account creation date, country, or something like that. Note that my team is pretty new to AB testing, so we may be asking for something that isn’t really practical haha.

Hi Christina, thanks for including GrowthBook in your research 🙂 In case it's helpful, we published The Open Guide to Successful AB Testing. It focuses on GrowthBook but there is a lot of information in there that is not dependent on using our platform.