Unfortunately for the publishers there is also a "I am not buying anything new for a while" crowd, or is that just me?
I have more 3E stuff than I will probably ever use, but might still buy more if I stay with that game (and by *I*, I mean my *group*)
However, as a dedicated fence sitter towards a totally new game (also known as 4E), I don't want to spend more money on stuff I may never use after next June.
So, I wait. This is not good for the publishers (sorry guys) but is the best choice for my wallet... which is NOT infinite in size.
Then there are sales of things I already want but don't have that tempt me to go spend, but on previously created products and while that benefitrs me, it still doesn't help the publishers with future projects.
Unfortunately for me and the publishers, I may decide next July that 3E is where I want to stay, but by then they may have had to adapt to 4E and we may both suffer... me from not having new 3E material and they from not getting my dollars on 4E stuff. It is a tricky situation and will continue to be so for another 6-7 months at least.