Originally Posted by
B747-437B
Avion usually offers bonuses on transfers to both BA (Avios) and AAdvantage at some point during the year.
The BA bonus just ended last month, but no sign of an AAdvantage one since Xmas 2010. With AA now in Chapter 11, I'd expect to see some sort of 25-50% transfer bonus within the next couple months if you are willing to wait.
I believe AA had one ending November 15th or 30th of 2011 IIRC.