Interesting idea. If you were selling a product though, you may not want anybody to pigeon hole it. Outside of commerce, perhaps they could suggest one for you to adopt? Or failing that, how about having 2 extra tags for commenters to fill in? Hmmmm. Interesting idea. I somehow feel that there is something in that, though it may end up being something else !?!?!? Perhaps a way of indexing personally saved content?