XboxAchievements.com has a quote from Assassin's Creed Game Director Damien Kieken explaining that offering microtransactions in Assassin's Creed IV: Black Flag is what allowed Ubisoft to offer multiplayer maps for the stealth/action sequel for free, avoiding a rift that would prevent owners of the game from being able to play online together. "Just quick notes here for example in our case," explains Kieken. "We are offering all of our maps… so all of the AC maps are free in AC4. The main reason is we don't want to split the community. We don't want to have players saying, ‘I have the DLC, so I’m only playing with the guys who have the DLC, my buddy doesn’t have the DLC, so he can’t play with me.’ It doesn’t make any sense." Thanks MP1st.