Pepsi has an on going promotion called the Iconic Summer. You get codes to redeem online for Icons that you mix and match to win prizes. The most notable prizes still left are Monster DNA headphones (retail $180) and 1 year of Mountain Dew. There is a Pepsi side and Mountain Dew side that both have different prizes.
So far over the pat week I have won 2 Mountian Dew T-shirts, 1 Pepsi Beach Towel and a Mountian Dew tumbler.
In addition to the prizes if you sign up and link your account to Pepsi Expereince you get 100 points for each code entered. You are allowed a max of 10 codes per day so that would be an extra 1000 in pxp (pepsi xp). A Pandora One 1 month membership is currently 4000 pxp