I think you are right, they are going to type in the name of the picture to try to get it. As a surfer I did it all the time and there are web boards that tell people to do just that. Surfers already play with urls anyways and hit 404's.
You would have to say something like:
http://www.thumbspot.com/daily/lsrb/new.html
Just like selling AVS memberships, don't give them any hardcore or alot nudity and make them pay for it. I like it!
If you did do random images, maybe putting a border around them like some content sellers do so that the surfers know which ones they can click, it may keep them interested.
Burtman
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