Last year I received a USBC dvd with the same letter. I threw the entire package in the round file. A few months later, I started getting e-mails requesting payment or to return the dvd. I simply ignored them. Again later, I got a phone call from someone requesting payment, or to return the dvd! I reminded them that because the dvd was shipped to me without my consent, it is considered free, with no obligation on my part to do anything more than throw it away.
Now, I also agree with BrianCRX90 that they are wasting time and money with this kind of promotion. There are better things that they could do, such as lane certification, getting every center to have working foul lights (god forbid!) and organizing with pro shops across the country to provide better support for new bowlers.