I use Gyft for about 40-60% of my purchases since they take BTC. This would be IMO the most useful real-world application and a game changer.
I agree. Gyft would be a pretty big deal.
But even if it's just gift cards direct from the marketplace, it'd at least be something.
If they get giftcards and/or gold+silver, then their loyalty program begins to get interesting. Someone getting $20+ (or however much) in free marketplace money each month probably won't think it a big deal, if their purchase options look like the typical crypto auction site (meaning a terrible version of eBay, primarily selling ebooks or junk). But if they can get $20+ worth of giftcards for free each month ... or a free silver coin each month ... forever ... then that loyalty program begins to look like a much better deal.