Hollywood disappointed with UMD

Sony and their PSP introduced UMD medias. That's the format used for games, as well as for films.
Yet, the sales of the latter proved disappointing. A blockbuster will reach 100,000 copies, while less successful movies will eventually sell 50,000.
Actually if the PSP is an excellent playing machine, it's not the ideal multimedia reader, especially for reading a film costing over 20 Euros.
To try and save the format, you'll see DVD+UMD packs around 40 Euros. This is still very expensive and you'll actually feel like you pay twice for the same movie.
It doesn't seem things will turn out better as Sony, a company with multiple and sometimes contradictory interests, sell Memory Sticks with ever increasing capacities, and ever cheaper, that allow stocking of hours of video that anyone might encode from their own DVDs, provided this is not illegal.