John...I have a pro account. I learned the hard way when I was using my free account and I posted the pictures from B-J two years ago. I only had about 100 pictures up...but I got so many hits from this site that it exceeded the bandwidth for the month in less than 6 hours.
Chris is right...the bandwith will reset every month...but if you exceed your bandwidth...no one will be able to see ANY of your pics.
So I went Pro...it's $25 a year.