Register for Uplay at the 'Main' menu to be able to spend Uplay points to purchase the following bonuses.

Assassin's Creed 3 Theme:
Purchase for 10 Uplay points.

Multiplayer Profile Items and Pouch Upgrade:
Purchase for 20 Uplay points.

Ezio's Oufit:
Purchase for 30 Uplay points.

Multiplayer Profile Items and Night Stalker Outfit:
Purchase for 40 Uplay points.