Patents are largely useless if you're small. They're very expensive to get, and once you have them even more expensive to defend. Moreover, a defensible patent is so narrow in scope that it provides very little protection by itself. Someone makes a small change to your idea and bypasses the patent entirely.

If your idea is good and you execute well, you have little to fear from large competitors. The larger the company, the harder it is for them to innovate. They're protecting their revenue streams and have less appetite for risk.

They'll wait for your idea to be proven before they consider implementing it, letting you absorb the risk. When it comes time for them to implement, you may have a large enough market share that it doesn't matter what they do. Or you may have made enough progress that it's easier for them to acquire you than it is to build it themselves.

One thing that does concern me in your description is it sounds like your idea is simply a feature, not a viable business or even a useful product. The fact that you're concerned with your idea being easily tacked onto an existing social site leads me to believe that it's really just an improvement on things that are already out there.

Features don't really stand alone by themselves. You need a compelling product and a decent revenue plan to turn it into a business.

Thank you for the reply as I can think bigger now and I actually did relief a little bit.

This is not a feature. This is an idea that will be the whole product whereas it also can be integrated with a business networking platform like linkedin, xing, etc.

This is not a 2 weeks idea by the way. We have been discussing it for months and still excited about it and hardly working on making it real.

You're right, it does sound stupid.

Execute. Put the idea out there. If it's good, you'll get traction, and that's going to be more useful leverage than a patent. If it's truly unique, you can pursue a patent as well, but don't let that stop you executing on what you have now.

'The big ones' are not scanning your webserver waiting for you to put out something then steal it.

Thank you for the courage and thoughts.

"Our idea can be stolen / integrated easily with the current big business networking web sites."

If that's really true, you probably don't have an idea at the first place.