After releasing QUBES, my first "commercial" game, I got about the offers from publishers (I guess) offering to promote my game for a fee. Is it the way to go i

After releasing QUBES, my first "commercial" game, I got about the offers from publishers (I guess) offering to promote my game for a fee. Is it the way to go if I want to make some money with it? I got some free credits on Google Ad and I'm running a small campaign trying to gather players. After 3 weeks I got about 300 installations, I feel this is a very small number. People tell me they like the game, some complained about the amount of ads which I now reduced, but besides that, I don't know how to get more people to play it.