I'm working through Walling's "Start Small, Stay Small" and I found a couple of niches that seem ripe for the picking. The problem I'm having is how to get a foothold (information products, apps, starting an SEM vendor, etc.). I haven't found much on evaluating how to make this sort of decision.

I lean towards building apps, but that's mostly my developer bias showing.

Do you have any advice (off channel, even)? Are there any resources you can recommend?