AT&T has a simple tool to calculate how much data you use. Very useful if you want to determine which Data plan to get, 200mb for $15 or 2gb for $25. With 200mb, AT&T says 65% of smartphone customers fall into this category. 2gb is for those who do not connect to WiFi daily and uses the 3G network or E network to get on the internet. Must have if you travel alot and use your phone. I fall into the under 200mb plan. My account show I use between 140-170mb a month. I rarely use 3G since I'm on WiFi all day. I must disagree with the data usage shown on my account...there is no way I use that much data. Something is amiss.