I was about the post the same thing. Not all movies are $20 (most aren't.) You can also purchase a single episode of some shows for a much smaller prices. Chappelle season 1 episodes are going for $1.96.
Which actually brings up the main form of competition that Walmart would be facing with me. Discover Card gives me the option of taking my Cashback bonus as Hollywood Video coupons. Each one is good for a free movie rental. There are 10 in a pack and each one costs $20 in Cashback bonus. This means that I effectively get movie rentals for $2 each.
So even in the optimal (for Walmart) case of me buying TV episodes for $1.96 each, my $20 would get me about 10 episodes. Meanwhile, my movie rental coupons would get me about 30 episodes (assuming a mere 3 episodes per disc and assuming that each disc requires its own coupon).
Of course, if you want to get picky about owning vs renting, then I could buy the entire fifth season of Smallville (to pick an example) for $39.99 (Amazon.com) versus buying it via Walmart's download service for $43.12. The usual arguments of extras and playing on DVD players apply.
