I imagine your ideal buyer is another (probably bigger) forum/community that also uses affiliates so "gets it", but not a single bookmaker because probably you

I imagine your ideal buyer is another (probably bigger) forum/community that also uses affiliates so "gets it", but not a single bookmaker because probably you make the most money by being impartial and affiliating with every bookmaker. Also you might want to talk to https://www.fubra.com https://www.fubra.com, who I have seen buy out a UK-based forum before. Maybe directly or via a broker (a sister comment has mentioned a few)