I was just looking up some old sales numbers and I didn't realize Trails of Azure opened to 127,938 copies on its opening week for PSP only. That's better than Zero, which was 84k - I was expecting it to be less since it's a sequel.
In fact, that means that Azure did better than Zero, Cold Steel and Cold Steel II if confined to single platforms (which all debuted at about 80k for their respective portable platforms, although the fact that CS and CSII are also on PS3 means that those titles are like 150k-160k on opening week.)
That being said, the fact that CS and CSII are dual platform means that they're the best selling Kiseki right now and are the 'big money makers' for Falcom.
It's funny that Ys has changed from being the flagship Falcom franchise that shows where the company is in its life to Trails being the central moneymaker. Maybe it's the relative drought for no-nonsense, traditional JRPGs that aren't panty quests.