I think it would scare away those who enjoy a good mystery who - at the time of the ID - don't feel as if they're being used by an opportunistic twit.

Case in point, I don't mind helping an identification thread when I think I can provide a helpful comment or some sort of insight. However, valuation threads annoy the living hell out of me ("Want to know what it's worth? Do a Completed Auctions search on eBay, dum dum!") so I stay out of that forum entirely - and woud avoid identification threads as well if it meant paging through that nonsense.

-Kurt