When we started the videos, I was going to just WMP, but there were so many different versions acting differently, that I decided to go with flash video. This has been pretty successful, very few people have trouble playing the videos.

This is from the HB help doc in the help section:

http://www.guitartricks.com/helpsubscriptions.php

How does monthly credit card billing work?
High Bandwidth subscriptions are billed $5 monthly and can be cancelled anytime. Recurring account billing happens on the 5, 15th or 25th of the month, depending on when in the month you signed up.
Signup Rebill
1-10th 5th
11-20th 15th
21-31th 25th
When you cancel, your account expires a month after your last payment. In some cases, you will get a few extra days when you cancel.