Before the “ban”(in this case operators banning themselves from US 
), my Partypoker (by far my biggest client over the last 4 years) player base was 87% US. I believe that across all programs 85% of players and revenues were from US.
Today, most new players are still from US, mainly (as before) thru microgaming programs. I’ve been really disappointed by the performance of virtually any non-micrograming program that i’ve tried. The only exception so far has been Casino Coins, where the conversion, commission and retention is acceptable.