Just Keep At It Mate~!
I've had the same thing happened during the past few failed attempts of having a group. As Enoki said, some floofs just don't have the actual commitment and we can't really blame them. Kinda like...a spur of the moment, y'know?
So just keep bringing something new to the table. Maybe you can ask your group members on some advice, hear them out. Let their voice be heard. Like in the newest one I made ( Fairly New ) I ask my most recent members what they like in the group and I got some pretty decent feedback, especially for the roleplaying.
So maybe that'll help them as well. . . .
I know I'm sounding like a broken record, but don't give up and just keep doing what ya love ^^