Developer Marcin Krzyzanowski had an idea for an Objective-C t-shirt and decided to see what kind of money he could make in a three-day sale. Marcin points out that he made more in three days of t-shirt sales than his app makes in a month.
Independent developers must have their eyes open for opportunities to diversify their income. It's difficult to make a living on the App Store and you need to be open to other ways of generating income. I've mentioned before that I am an Amazon/eBay seller. I enjoy it and it works great with app development. When development is slow, I buy products to resell. It's also a great change from standing in front of my laptop all day. If you're struggling to make enough with your own apps and contract work, consider other ways to make money like an online course, blogging, or an iOS newsletter. ;)
Selling t-shirt > selling mobile apps. Dinosaurs. by Marcin Krzyzanowski