Very interesting discussion at your blog. (Cool, isn't it? We got 176 unique visitors yesterday. That's a steller day here at the blog.)
Here's a hypothetical situation:
Suppose a new, unknown author wants to promote his/her book and asks to do a book signing, only to find that bookstores don't want new, unknown authors to do book signings. In order to become more well-known it would seem that this author would need to do book signings, yet the stores only want well-known authors. Isn't this a catch-22? How would said author overcome this obstacle?
Bookstores aren't the only places you can do signings. Public libraries will often do signings. You have to bring your own books and usually agree to donate a portion of the profits. Sometimes it works better if you can get several authors to come talk about literacy or something, and then do a signing afterward. Also try senior centers, schools, other community fairs and events, book clubs, business or service clubs, etc.
Or offer to do a launch party at the bookstore. If you can guarantee to have a certain number of friends and family show up to your party, planning to purchase at least one book (whether yours or someone else's), they might be willing to work with you. Of course, you have to be able to actually get those people to show up, to buy a book, and to tell the cashier that they came because of YOU.
You can also do virtual booksignings. This doesn't get quite as much notice from the bookstores because people don't go into the bookstore to buy the books. But you can have people buy the book by a certain date from you and then sign the copy to them. If you can show that when you did a virtual signing you had 100 people order books from you, that would get the bookstore interested.
Authors, other ideas? What have you done to get a bookstore to have a signing for you?