You know, I have two blogs. I have an option for people to get automatic updates etc. Often times, I see that people simply don't want to do that, however, most of my traffic is return trafffic
So, what does that tell you? People are FINE with visiting your blog(s) but don't expect it to work the same way a mainstream blog would be, it's adult. It's taboo.
I would say if you can find a free plugin or work with mailchimp (for free) why not? I wouldn't put much on it. Just focus on constant and frequent posting. I promise you'll see increases in traffic.
Adrian