The gambling ads we see most often are on Facebook because Facebook has a very large number of users which makes casinos try to get more users from Facebook. Maybe there aren't many applications that accept cryptocurrencies right now, but as time goes on, many applications will accept payments via crypto. The Bitcointalk forum is a medium for casino promotions, and we have seen many new casinos successfully running their promotions and developing into one of the recommended casinos.
I have never seen gambling advertisements on Facebook, maybe I am not used to using social media for gambling activities because the system will detect and work based on the search interests used by users, there is also a discussion from Facebook about advertisements which must also be understood
https://www. facebook.com/business/help/345214789920228