I just look at it in time spent. I spent more time in de fediverse because of this app. I don't want ads, I feel like it's worth it. Especially the pine Time, 20-25 euro no ads option.
I think they are comparing it to the value they get from the service as an individual. As a consumer, I don't care about the company's overhead. I would only care if I get my money's worth with the service I'm paying for.
I'm considering annual too, but I'm waiting for two things before pulling the trigger. First is push notifications, second is the release of Boost for Lemmy. I want to compare features and prices before making a decision.
Right now there is no other app that feels as nice as Sync, and I don't mind supporting that, but Boost is a worthy challenger. And I could only really justify paying for one.