When you sell service on the web like custom development, one day, you may want to try the product side. I made several tests and finally i've decided to sell a WordPress plugin.
One of my questions was "Is it still possible today to sell plugins and win money for that ?". I don't have the answer yet but read this blog post.
For me, first feedback is really cool. I sell my product regularly but it's not my main activity. I want to increase revenues related to this activity but it takes time. Dissociate income and time spent and not just "sell time" is something that has been questioning me for a long time and I clearly want to direct my efforts towards this.
This tips we can read everywhere is really true : "go and test quickly". Otherwise, we never take action.