[Someone1234]

So if the OP's idea was a Twitter clone and they put "marketing and promotion behind it" it will "work out?"

In my view the idea is the most important part. It doesn't have to be a "great" idea, but you have to have some kind of basic concept and have to look at the market to see if there is any kind of need. That's particularly important if you're spending $1K/month behind this concept and need it to give a return.

[kocsmy]

"niche" - to answer your question: no it won't. I can find you a couple of blogposts about the importance of ideas. It's just overrated.