First, a Web service that "meets an unmet need." Back in 2005 I built a "code snippets" site using the then-nascent Rails in just over 24 hours. I then spent a second day making the design more "Web 2.0" a few months later, but otherwise did little except mention it here and there and add my own code into it. It made ~$800 a month from Adsense for a couple of years and then I sold it to DZone for $30,000. Perhaps the…
How many pages do you need for an e-book typically?
This attitude is more obvious with screencasts. Even 30 minute screencasts can sell OK at $9.. and the amount of effort to put that together is far less than even a, say, 25 page e-book. You just need to hit the right stuff.
All that said, my basic investigations show that in the general programming world, books of $20. But this is all very arm-wavey.