Paul,
Joe Polish has a hell of a lot of flyers A3 pink is only one of them. Over the years I used to experiment with leaflets and my best ever has been A5 card, folded, printed both sides, Black print on White card. People will keep these rather than paper ones of any size. The message has, of course, to be spot on, the way its set out, too, is equally important. Most print shops have a general idea on setting out, but it needs to be more specific than that. My best leaflet evolved through 5 years of expererimentation. These card type leaflets are more of a detailed more informative business card than a flyer and cost too much to be mass distributed and are better suited to a slow drip, than an immeddiate response requirement.
Dave.