I also don't always see the new DVD releases I want in stores when they come out, which has occurred with certain Sesame Street releases as well as a lot of DVD or Blu-ray releases that are not releases of recent mainstream films. I know, I could order it, but I don't really order online often.
Rentals are good for three days after watching, so if I decide to go that route, I'll have to pick a time when there'll be plenty of time to rewatch.