1. The GB/month is an easy to understand measure that most
people understand. Network traffic is usually measured in kbit/
sec or Mbit/sec chunks, but unless you work with these units
much it's hard to grasp what it really means.
2. It's hard to know--you just have to see what happens. Most
of the providers beyond the budget hosts will give you a base
bandwidth with burst. For example, you might have a 128-kbit/
sec base with a 10-Mbit/sec burst. If you get slashdotted you
might be ok if the the 95% average of your usage (measured
over a month, usually every 5-minutes) is still below your base.
If you go over you have to buy bandwidth to cover your usage.
Exodus bills in 1-Mbit/sec chunks while Above.net (last I
checked) will bill in 256-kbit/sec units.
Photo.net is in the 5 - 6 Mbit/sec range, or (very) roughly 1.5
to 1.8-TB a month.
