If you haven't viewed it, you should be able to keep it IMO. Instead of a time limit, it should delete 24 hours from the time you have started watching the movie. These boxes have hard drives for a reason...
When you go to the movies you typically intend to view the movie that day (you can purchase movies in advance). If you miss your showing the theaters will typically not refund your purchase or allow you to view another showing. Moreover, you can not return to the theater to see the movie again since you already paid for it previously
In a simular fashion if you cannot find time to view the PPV movie within 24 hours maybe you should delay that purchase or purchase the DVD if you anticipate viewing it multiple times.
The reason these boxes have hard drives is to facilitate the DVR fuctions and not to retain proprietary data for weeks on end. If you really want to record it to watch it over and over, just wait 4 months for it to come on Showtime and record it at that point in time. At this point you have an EULA that allows the recording of these movies.
To me, it's the individuals who are looking to take advantage of the systems that cause the rest of us to feel the oppression of rules such as the DRM. I'm not saying I won't gladly strip media of it's DRM if I purchased it, however the underlying meaning of PAY PER VIEW is very clear to me
