It really depends on the originality + depth of the idea. If you think of something like "a cool social network", then yeah, it's worth (less than) a dime. But

It really depends on the originality + depth of the idea. If you think of something like "a cool social network", then yeah, it's worth (less than) a dime. But if your idea is a somewhat detailed version of Google's search engine algorithm, and you're the first one to think of that, then it's probably more valuable than what the cliche prescribes. Personally, I believe that good ideas that result in successful businesses are worth keeping to yourself, as long as you plan on making something out of them.