My father was in finances all his life, running a bank when I was about 18. It was in late 80s. Often I talked about my "ideas" and bottom line of his reply was "son, ides are worth 1c". I wasn't expecting that, couldn't completely agree with that, thought maybe someones elses ideas are worth 1c but not mine. It took me MBA degree and years as CEO of IT outsourcing company to fully understand it. It is delivery that counts! Your knowledge, passion, time and dedication you're willing to invest to make the idea work. Today, when I'm in situation to invest in some "ideas", I'm sure I'd never invest in idea only. Investors put their money and time in the team, not the idea itself. Only after they detect that passion and dedication they will consider the idea.
This changed the way I think some time ago. I was now focused on people, dedication, PRODUCTs and not only ideas. But being in IT as long as in management and economics, I have to continue to another "truth" that I learned even later. We were proud that we skipped "talking about ideas " stage of our careers and were doing real products and services. Being in IT we focused so much on technology aspects, quality, features, design, etc. Often we were "angry" how bad products/companies do better than us. Then, another simple sentence hit me, I think it's part of american business philosophy but I don't remember who said it. It was something like "anybody can have a product". It shocked me a bit at first. We just "reached another level", put praise on ideas behind us and started working on the real thing and now somebody says that just anybody can do that! That it's nothing important! What is then? Well, bottom line of this, as I see it now, was just emphasizing how sales, marketing and money/investment is equally (or even more) important to success of the product than it's technology/design.
So why do I mention this in addition to "ideas are worth 1c"? Because most of us here (like my company back then) are programmers or in some other part of IT and we all tend to (over)emphasize our part of work. But you have to realize there is so much more to successful product that is not directly related to IT.
Back to "idea"... this should give you some picture what a long way lays between an idea and a successful product. It should also show you my opinion about sharing ideas. Just do it. You'll see benefits of it along the way. And there are so many more poorly executed ideas out there than hidden ones. So, you'll never run out of the ones you can deliver if you have what's needed to do it.