Getting back to the original question (To post or not?) I think the answer is simple: If everyone kept their secrets to themselves, FT would cease to exist. Everybody would lurk, never find anything and so nobody would share.

One issue that hasn't really been addressed: What's the downside for the original poster? Not much. Sure, the deal may eventually "dry up" (e.g., hotel realizes it has a $10 room rate on its web site), but by that time the poster has already taken advantage of the deal.

Contribute and feel good about brightening someone else's day.