As a hypothetical since I'm working on a game that may use this, how would you feel about the following? For a multiplayer .io-style game, you get a score per level, and a cumulative score. The top few players by cumulative score are shown to everyone and celebrated, etc. If you ever get zero points in a level though, you'll lose your cumulative score - unless you watch a video ad.
Is that acceptable, or does it feel like blackmail?
(FWIW I'm discussing this with a lot of other gamedevs too, but since you brought it up I figure you might have a "different community" opinion worth my knowing!)