Everyone is quick to say that special recognition and perks don't happen when you fly on your birthday. I have counter evidence:

I recently flew ORD-STL on AA Eagle operated by Republic, and after the door closed a flight attendant made a celebratory announcement about a passenger's birthday. She then proceeded to move the birthday couple from their Main Cabin seats to a first class bulkhead across the aisle from me (out for which, as a US Platinum, I had the pleasure of shelling $30). Over the course of the 40-minute flight they were showered with Jack Daniels and the flight attendant gave them one of everything from the buy-on-board bar cart—while I munched snack mix and was more or less ignored.

If you one is brash enough to announce a birthday to an airline crew, who knows what might happen.