I think sometimes a lot of members aren't active past the point of reading and many aren't officially members as well. That still doesn't stop me from responding to almost every review I get. I still feel like it needs to be an interaction. I know it has to be hard for prolific readers to respond to everything they read; there's so much out there.
Some of it can be the story line. A nice dramatic romance in a high school or college age setting seem to grab a great deal of attention but I don't plan on writing in that genre unless it really is the story I want to tell.
My numbers have been good and improving as I go along, so I'm quite pleased with that, but I wish I could maintain the feedback I often get from the start. That would be the only thing I'd like to find a way to improve on. At this point, with the time I have, I'm promoting as best I can and it seems my readership is growing slowly, but it is growing. I feel like I haven't been doing this very long and I'm shocked at times how successful I've been.