Rent a dog?

Here's a novel idea for those people who don't have enough time to own a dog full-time. Like job sharing, you can be a "master" at your convenience.
While it's a laudable idea in some respects -- namely it helps the animals who aren't adopted outright -- it really makes me wonder about the motives of a part-time owner. The fun thing about having a pet, particularly a dog, is the bond you create with the animal over time. The dog becomes part of the family.
Can that really be done part-time? Makes me think of these dogs as an accessory item.