In the best of all worlds, I wish I could rent to own when it comes to my watch hobby. It takes about a month to see if a watch is going to fit in my rotation. Even watches I like a lot grow tiresome and it's time to send them on the way.
That's why a watch rental service might be appealing. I doubt there's a big enough market for it however. Also, the idea of watches, some costing 2K, circulating in the mail and entering smokers' homes is disconcerting.
Too many problems, too small of a market. Probably would never happen.