You get one prestige token for every previous version of COD that you prestiged in at least once. For instance I never played COD until MW2 came out and I prestiged in that as well as Black Ops therefore when I got to MW3 I already had two prestige tokens. Once I prestiged in MW3 I got a third token. Since I did not read about prestige tokens and the purchase options that I could buy with them I wasted one on 2 hours of Double XP. I say I wasted it since I could get lots of Double XP time with codes from Mtn Dew caps and Doritos bags.
I then looked at the Unlock Gear option and found I could unlock most any weapon or perk. Since I am a stealth player with average reflexes I decided to buy Assassin Pro which keeps me from glowing on every enemies radar. I wasted another token on the RPG also. This means that every time I prestige I only have to play one game with the default weapons and setup. I always get to level 4 after the first game and I can then setup a class using the UMP, RPG and Assassin Pro. With those I can pretty much kick ass. In no time at all I have Blind Eye and I am free to cruise the maps looking for prey. In hindisght I would easily trade the RPG for Dead Silence since I prefer stealth over firepower any day. But on a dare I bought the RPG and now must live with the consequences.
Use your tokens wisely. I didn’t. A lesson to learn from.