I see a lot of people using blogs as a way to enhance intimacy in personal relationships.
For adult blogging, I imagine talking about sex, masturbation and fantasies in much the same way would be of interest to those explorers of the erotic mind. Not everyone responds primarily to visual stimulation, afterall. It's an intimacy thing - getting to know how a person thinks and causing an erotic reaction within that mind can be very arousing.
Personally, I'm more attracted to people I have a feel for then people I've rarely interracted with, and flirtation is a sure fire way to get me horny.
EDIT - and when I get horny I like to use my Fleshlight. (That's product placement for you.)
