It's a real person (not a bot) who is not accessible via the web (no published information) but who nonetheless posts constantly to blogs, forums, etc. What stands out is her constant hyping of Judith Orloff, MD.
I found nine pages of google entries with that specific earmark. I found easily 143 entries containing "susanchap21 and Orloff" together. Sheryl and I both got hit. I published the comment at first, and then realized what was going on and deleted it.
I only looked closely at a few of susanchap21's posts. In one instance she claims not to be connected to Judith Orloff (somebody asked her directly). In other instances the unsuspecting have answered her comments with carefully thought out responses, several paragraphs long. Why? Because susanchap21 will actually read enough of your blog to make it look sincere, then she invariably touts Doctor Orloff's work in some way, providing a helpful link within the comment.
I can't prove who she is or who she works for, but my personal opinion is that this is a particularly deceptive guerilla marketing technique. Another personal opinion: it's not ethical to feign interest in another person's sincere creative work in order to snipe in an advertisement .
Sheryl is writing about this too. We got nearly identical comments within 24 hours to a couple of our blogs. If Judith Orloff or her employee wants a free ad on my blog, she can offer me a free ad on her blog or website and I'll consider it. But I don't like being tricked.