How much robux should I spend on ads?

Ok so my game is good and there’s no bugs, it has a fun concept and challenge. I spent 500 robux on 2 sponsored games and whenever I was in the game random people would join but the server would never go over like 5 people. I also did another sponsored game for 2.5k but I think I wasted my money cause it kind of had the same effect. What’s my goal? My goal is to have at least 50 players playing the game when I’m not there. I’m not asking for it to be on the front page just enough so the game gets used. I have about 6k robux and I am good at making writing/marketing so making a good ad isn’t the problem. My problem is usuing the robux smartly. I wanna make some user ads and sponsored games. I’m also thinking of doing the burst method for a bunch of ads. How much should I spent on what ad and how many players could it get me. 50-100 players playing at one time would make me happy cause then I can always go bigger.