You need rep, everyone needs rep, its a grind, but this week its an easy grind. You can solo most heroics now with Ashran pvp gear, I've been taking my 5 hunter team through heroics with little trouble. So no more excuses for not being exalted.

Here is the factions you're awarded reputation with (20 per trash 400 boss):
Arakkoa Outcasts: Skyreach
Steamwheedle Preservation Society: Bloodmaul Slag Mines, Upper Blackrock Spire
Sha'tari Defense/Laughing Skull Orcs: Auchindoun, The Everbloom (no Trading Post required)
Council of Exarchs/Frostwolf Orcs: Shadowmoon Burial Grounds, Iron Docks, Grimrail Depot
Battle Net link
WoWhead link