Some reasons: a) Ship to other countries b) Unlocked phones so they can use it with other Carriers. c) People who are not upgrade eligible from ATT and want

Some reasons: a) Ship to other countries b) Unlocked phones so they can use it with other Carriers. c) People who are not upgrade eligible from ATT and want a iPhone now (My wife) d) People who dont want to add a 3g plan since they are in wifi areas most of the time etc.