My iphone continuously asks me for my itunes password

I just got an iphone 5 and it seems like everytime I move my iphone is asking me for my itunes password. Some days it happens over 100 times a day. I like to use Wifi and whenever I dont have wifi i just use my data plan. I just dont understand why my phone keeps doing this. At first I didnt really care but this has been going on for over 2 months now and its getting in the way. I used to always put my password in but then it would just ask for it again 2 minutes later, so whats the point? Does anyone know anything that will help me. My iphone 4 never had this problem im not sure what it is.