I'm still very much a novice, but so far every gap I've traded (with the exception of three this week, which are still open) have closed. This has been very profitable, especially when the gaps widen. I had a GBP/Nzd gap from 09 August which widened to 450 pips at one point, and only closed today, about five and a half hours ago.
It's very straight forward and could be worth a look, even if you tested them on a demo.
