People will make posting here a full time job. Give it time.
It's always a bit subjective. You can measure based on a number of criteria
1: Filter by whether or not the site is dedicated to role playing.
2: Filter by whether or not the site is dedicated to adult material.
3: Go by total forum postcount.
4: Go by role playing postcount.
5: Go by total posting rate.
6: Go by role playing posting rate.
Applying both 1 and 2 and going by #3 lets you use big-boards.com or similar forum directories to pick such places out (thebiggestboards.com does not exactly have a comparable selection). There really never was more than Adult Adventurers, Elliquiy, and DRP on that count, or if there was they are doing a good job of keeping it secret.
Literotica's SRP forum is the only other adult community with significant role playing activity to rival DRP's or Elliquiy's activity, and of course, there it's just a subforum. In fact their boards would be a wonderful recruiting target.