So I'm getting a smartphone from AT&T soon, and I'm a little confused on the data plan. I have wifi in my house, so if I use this instead of the internet through my cell phone or whatever (while I'm at home anyways), it doesn't count against my plan right? Which means I could be on Facebook, and watch all the YouTube videos I wanted and it wouldn't put me way over on my 2GB plan..? I just want that cleared up for me! Also, I have four smartphones on my plan, is the 2GB for each individual phone, or do all four of us have to share the 2GB limit? Thanks in advance