On our own gift ideas site, we were working on this problem. We started out with getting people to suggest gifts to each other, much like Stack Overflow handles

On our own gift ideas site, we were working on this problem. We started out with getting people to suggest gifts to each other, much like Stack Overflow handles Q&A. We got to a point where we were able to suggest things to people based on their shared interests, using an algorithm and all that accumulated human-based suggesting. It turns out that when you get enough somewhat generalized interests in the mix, you create something of a profile that relates pretty directly to what you might like as gifts. If you and I both like movies, wine, cooking and travel, we probably will both like the same kinds of movies, books, or trinkety, Etsy-style gifts. Our difference is that we directed ourselves at the frustrated masses who were trying to find gift ideas, and couldn't come up with any, which turned out to be very difficult to sell, in terms of the right marketing message. Still working on it!