Has anyone at Stackexchange written open about their revenue model? Seems similar.
You do also need to keep in mind that you need to make sure the ads themselves aren't serving tracking garbage or outright malware, even if you do not offer precise behavioral targeting or even store behavioral data.
You can maybe also sell fun premium features like Discord does with Nitro.
Our idea at the moment is to act like reddit ads do. Advertisers essentially make a post without anything more than a title, description, image / video and a url, with the image / video hosted and scrubbed by us. This will most definitely take careful design but your point is valid. Right now it's a delicate balance of not getting ahead of ourselves but also not setting ourselves up for failure due to poor planning.
Premium things is something Snapchat tried out for a bit with bitmoji, though to be honest I haven't looked deeply into any available data on how that worked out for them.
You do also need to keep in mind that you need to make sure the ads themselves aren't serving tracking garbage or outright malware, even if you do not offer precise behavioral targeting or even store behavioral data.
You can maybe also sell fun premium features like Discord does with Nitro.