This is geared toward the heavy downloaders like movies and music and such. AH doesn't send a ton of info, thats why a dial-up connection still works fine. Right click "My network places" and select properties. Double click on the hispeed connection your using. A window will open write down the packets sent and received, then go fly for a couple of hours. Then check the numbers again, and do the math. My son is a geek and IT guy at a software company. He was running stuff from home for work as well as playing games half the night with his computer for over a week, and he almost hit 1 gig.
Unless you spend a lot of time downloading stuff I wouldn't worry about it.