I got my first yellow letter ( follow UP)

[Jay Hinrichs]

Well called the number on the yellow card... No return call that was 3 days ago.

Obviously I would think if your going to go to the time expense and trouble of direct marketing one should probably return calls ASAP.  Its funny how people handle this stuff

[Jay Hinrichs]

@Account Closed 

  or maybe its like Mike Q talked about some won't call you back unless you call them multiple times as they want to make sure your motivated.  Don't think that strategy will work go good these days. Not with hundred thousand BPers out there all learning the exact same techniques.