-Why there is no ads companies for html games but so lot for mobile games?
I'm guessing it's because mobile games are meant to be played within one screen, not a browser, so there are more ad companies willing to focus in on the mobile gaming aspect.
Browser-based games are generally left to ad companies that support traditional website ads. So Google AdSense and the like.
There's probably a better way to word that, but nonetheless it seems to be true.