Don't throw away an idea because someone else has already made it. This is crucial. People completely underestimate the amount of money you can make as a runner-up, or even as a 5th or 10th-place service in some markets. Most of the products I'm involved with have made me quite substantial amounts over the years compared to the minimal time required to upkeep them. There's at least ten companies I can name at an instant that do almost exactly the same, yet I still make money doing the very same thing. Appreciate the invaluable advantage a market-proven idea brings and focus on whatever its target audience lacks or loves most about the most-popular offering. It doesn't mean you have to copy something (where's the fun in that), but consider this if you start working on something and then come across someone who's done the exact same thing with good success. Don't give up, use it.