Book Depository site has an interesting feature: you can watch people shop for books.
At first this seems like a dumb idea. Who would want to do this? But then I started watching it with a certain fascination. It's sort of a live "Best Seller" list.
But I watched it too long -- the sales started to repeat, and I started to see longer times -- instead of "18 minutes ago" there were ones "83 minutes ago", which undercut the voyeuristic appeal and made this seem a lot more like a way to show paid advertising.