Not sure if this is what you meant or not, but while some of the discount comes from the TVM side of things, I'd venture to guess a much larger source of the di

Not sure if this is what you meant or not, but while some of the discount comes from the TVM side of things, I'd venture to guess a much larger source of the discount comes from the fact that they have locked you in to a 6 month pass. If you picture the monthly pass as a monthly subscription, then think of a reasonable retention rate for this situation (something less than 100% month-over-month), the value of guaranteeing 6 purchases up front starts to become significant.