Less than 10% of our sales numbers are from the ebook. The ebook was just a side project to see if we could share some information and make some extra money at the same time. You'd be surprised at how much ad revenue these apps make. Check out how much the paper toss guys make with just 5 apps - http://www.develop-online.net/news/36155/Paper-Toss-dev-make...
I've actually been doing development since senior year high school. Started with ASP then PHP, .net, c#, java with gwt. I don't know if I'll ever do any of my own development again though. I do enjoy programming, but I enjoy doing other things more honestly =).
We are and have indeed been winging the whole business. We're no business experts, we've learned a lot going through the process. It hasn't even been 2 years yet. This was our first "face to face" interview. We're not great public speakers either haha. Just going with the flow and we've been very fortunate so far.
Used to be SW devs. I used to do .NET programming for a big DOD contractor, then worked for a local internet startup for while, but why talk about my old career? That would have been boring. Plus as we tried to explain, at some point you have to let go and not micro manage every individual stat and app. I'm sure if we did that we could make some more money by optimizing, but that's not what our business approach was about. We wanted simple, stress free which gives us time to do other things. We're not experts, we don't have a degree in business or anything like that. Just 2 27 year old guys from San Diego who wanted to make a couple iphone apps.
We also use transpera and greystripe in some of our apps.