Well technically stuff ordered online is typically paid for before receiving. Always makes returns a bit of a pain.
edit: Oh, and what about memberships? You pay for the gym before seeing any results, and looking at most people in the gyms, I'm not sure they are getting what they need.
Oh and wine memberships are pretty tricky, since you pay, then have to wait for them to release, and even then the bottles might not be aged well enough.