Hi RobertB.
I read lots of romance and (I guess what some would consider) erotica. I just make sure my parents don't know b/c it can be a little embarrassing!
They would probably pass out if they read some of these books that I buy!
Not sure exactly what info you need but here are some ideas.
Will you be able to offer ebooks by publisher? If so here are a few good romance and/or erotica publishers - Harlequin, Samhain, Ellora's Cave.
Harlequin (eharlequin.com) would definitely be good to have - covers a wide range of books (from "tame" romance to spicy stories) b/c they have so many different series (Harlequin Presents, Silhouette Desire, Blaze, etc).
Both Samhain (samhainpublishing.com) and Ellora's Cave (jasminejade.com) deal with more "erotic" books than Harlequin. Both have really great authors and their websites give a breakdown by category (like paranormal, erotica, historical, etc).
Paranormal and shapeshifter romance books are really popular right now. Also historical and romantic suspense.
One good site to check out is allromanceebooks.com - they have their ebooks separated into categories like paranormal, shapeshifter, erotica. That may give you some ideas on what is popular right now. Fictionwise.com also categorizes by romance and erotica.
I'm really not sure what most people consider "erotica". Some books that I think of as romance others may think of as erotica. To me it's a pretty gray area.
Does this help you at all? Did any of this make sense? I can also give you more info (like authors, series, subjects) if you need that.
Have you thought about posing this question on any other MobileRead forum like Reading Recommendations? You may get even more suggestions and comments from those who don't look at the Astak forum.
P.S. Just wanted to mention that I love my maroon Pocket Pro. I've had it for about 3 months and I'm so happy I bought it!!
Weezie