Apple has been pushing content in iTunes largely for use on iPods. Those who watch on a computer or via

TV have been in the minority in the past. That being the case, any rentals must take into consideration that they are likely to be used on a portable device. If I want to buy some movies to watch on an iPod before a trip I will likely want to have them available for the entire length of the trip, including the return trip. That means a 30 day from purchase usage limitation is probably the best fit for the way the hardware is likely to be used. A limitation of 24 hours from first time played could be inconvenient for families but is understandable from the studios point of view. If the consumer intends to watch the video many times they might consider buying instead of renting. Still, whatever terms Apple provides must be very favorable in order to lure customers away from other distribution methods both legal and illegal.