How many players is assassins creed brotherhood

Assassin's Creed: Brotherhood is a 1-Player game offline. However, you can play it online against other players as well (up to eight players). There are multiple games modes that vary from Free-for-All Deathmatches, Team Deathmatches, or matches with specific objective such as capturing chests. Currently, the Brotherhood multiplayer is very low in population, but the newly released Assassin's Creed: Revelations will be much higher in active online players.

Sources: I own this game.