Their regular giveaways and generous bonuses were one of the primary reasons why I decided to Stake from the last couple of months which is why I am not surprised to hear that they are helping charities too.
This just makes them more reliable in the long term just like Primedice. They continue to pull in big numbers thanks to a variety of challenging games(Example: Current wagering races).
Stake had one thing that was above everyone else in their ruling which was trust, they are trusted by everyone in the gambling community and they are strong candidates for the best casino out there not because of their games or not because of house edge, certainly not promotions, all because they have been around for a long time (including primedice its 6 years) and never scammed anyone before.
However, right now we are seeing newer places that gets some attention too, I personally like crypto-games and windice obviously because they are doing a transparent running of casino and they have a great support that helps everyone but at the same time there are others too like eosbet doing some dapp deals with decentralized ownership of the casino with their tokens as well. Stake is still the leader right now but I am sure they will get more rivals soon.