Why does my iphone use So MUCH data?

I run an iphone 5 on verizon and my data plan is either 4 or 5 gigs per month but i am consistently over by A LOT, in december it says i used 13 gigs, and i have no idea how thats possible, i may have watched 2 or 3 netflix episodes, and i check facebook and instagram regularly, but other than that i dont use much data, how is my usage so dang high?

IDK if this could be it but if you double tap the main button at the bottom of the phone it will show all of the apps that are running. Then press and hold the app until a minus sign appears and then close all of them. If you leave the range of your wifi with pandora or anything else running it will keep using data. I've done this before so be sure to close the apps like I said.

NETFLIX! DUH!

online video streaming… Online gaming… Online radio streaming… Online music streaming… #1 data hogs!

I suggest you chill out… Use a data tracker app… And use WIFI as much as possible…

Do you realize how much data video uses? Its a ton, only use video on wifi only. Problem solved.