What frequency caps does StumbleUpon use?
Each unique URL is displayed at most once to each member of StumbleUpon. The same member will never see the same URL twice. If you want to increase exposure, create a new campaign with a different URL. Providing a few different pages on the same theme is a great way to drive your message home. Try to make each page interesting of its own right, with some unique content, even if overall the pages are fairly similar. For example, if you have a DVD or book store, you could make different campaigns for each genre.