Instituting advertising is guaranteed to reach your existing user base right away; those who hate ads will see them right away and quit right away. Removing ad

Instituting advertising is guaranteed to reach your existing user base right away; those who hate ads will see them right away and quit right away. Removing advertising doesn't have the same kind of immediate effect because the "audience" for it is people who haven't even heard of your app yet, and have no idea whether you're ad-free or not. (Here I'm discounting the possibility that there's a bunch of people waiting, hoping you eliminate ads so they can finally join.) So the effects of removing ads probably have a much longer lag-time, governed to a significant degree by the usual mechanisms and rates of user acquisition. Edit: you can also argue that the pre-existing users of an ad-free app have to some degree self-selected based on a hatred of ads, and that in a more general sample, the proportion for whom ads are a deal-breaker might be lower than 1 in 10.