i got this idea from alexander elder - not the EXACT strategy, but the general idea of betting on the long-term trend during a pull-back. it just made logical sense to me so i've been doing it for a while.
personally, i like to wait until the short-term trend (the 20 DMA) has not only pulled back but has begun to resume it's trend - i'm a "johnny come lately" kind of guy.
all that to say - "sure, why not?" i think it's a good way to jump onboard.
sometimes we just miss that first dot!
-ja