It would help to get some more details, but the rule of thumb is to fail fast and fail often. One of the executions will be a winner eventually.

However you need metrics in place to determine how you failed. Self marketing is usually going to result in a poor performance. You need to involve a firm who does that kind of thing and also know you will need to spend money in order to generate exposure.

If all you have is a concept then you're doing it wrong. You need a prototype and it needs to work and you need to deliver goods or services to market in a way that means you're easy to deal with.

Failing that you'll never get out of the gate.

Again, what's the concept and I'll tell you if it's a dud or not. Never be afraid to talk about your concept openly. For example: Facebook was facebook because it was facebook... the execution was great not necessarily the concept.

Shit if you pitched the concept before Facebook you'd get laughed at... but how it was executed was the reason it became successful.

There was Myspace... but they didn't execute nearly as effectively.

So again: what's the concept and do you have a prototype and can you deliver to market now in high volume?