By gaining reputation with the Stormpike Guard or Frostwolf Clan, players become eligible for [rare] and [epic] equipment rewards, as well some consumable items. Items from the Stormpike/Frostwolf factions are identical in most respects, though some have minor differences. Information on Alterac Valley rewards can also be found at the Official Site. Because the rewards for high reputation with these factions are generally useful, and because reputation can be obtained quickly and easily in AV, grinding rep in AV is a popular activity for casual PvPers.