If you’re talking about indie game developers, the way to go is to sponsor popular Twitch streamers and YouTube producers. If you know who these content creators are, you know a great deal about the tastes of their audience without having any identifying information from the audience itself.

If you write a game that the streamer/producer really enjoys, they might even continue to play your game after the sponsorship ends. This is the dream scenario because it’s free advertising that can sustain your game long term. These content creators can also provide a lot of valuable feedback because they tend to become experts at your game over a long period of time.

There was a great article in Wired recently about NPO’s efforts in the space. Unfortunately it’s not available as a service and is only an internal platform but there is definitely a model ripe for working on there.

https://www.wired.com/story/can-killing-cookies-save-journal...

Killing non-privacy-friendly ads is a great way to open up that market.