It would have to be people. In the past, i've focussed on the idea but as you'll see below, efforts have shown that the people are much more important. As much as i'd like to, i've come to realise I can't do it all myself.
I am just about to start my 3rd and 4th attempts at doing something from scratch. Fingers crossed i've learnt from the past!
A bit of background about me - I love technology and what it can do. I think the biggest thing for me is that, simplistically, when you have a problem identified, you can create software to solve it. There aren't many other fields I can think of that can achieve the same result. Whilst I come from a business background, I do enjoy keeping up with the technology side and have found that this has paid great dividends over the years as I have been able to at least understand (to a certain degree) the technical inputs to a solution.
A summary of attempts is below:
Attempt 1 (2003) - Whilst studying, had a great idea (as part of a university assignment) to provide hospitality consumables (disposable coffee cups, polystyrene juice containers etc.) to vendors for half price and subsidise the remainder of the costs (and our margin) with targeted marketing. I joined up with 3 other guys from my class hoping that their enthusiasm would continue. It didn't. Despite having a unique 'in' (We had a patent on a innovative, cheap cup holder to go with the other consumables), we all progressively lost interest as various challenges arose.
For me, the reason I brought the other guys onboard was I knew that selling cups/cup holders wouldn't challenge me (technically) and not being a salesmen, looked for those types of qualities in the others. However I now know there is more to success then a good product and being able to sell.
Attempt 2 (2005) - This idea was definitely right up my alley. It was technically challenging, there was a clear need and there were no operators in the market with a service even close to what we proposed. This time I partnered with 1 other person who I had previously worked with. After writing out our requirements etc. and having a go at the design wireframes we enlisted a developer to get the ball rolling. Unfortunately this guy took us for bit of a ride and, you guessed it, we didn't end up with a prototype. I kept trying to get it up but just this year decided I'd missed the boat.
The idea was a combination of bankrate.com, billshrink.com (not allowed to post hyperlinks yet) and a ratings framework I developed for retail banking products. If there's anyone reading this that wants any of my research let me know. Whilst the product comparison and cost saving pieces have been done, I am yet to see the ratings although I have stopped looking as much in the last 12 months. The rating framework would ensure that at the point in time a user is looking that they are getting the best product for their need/use.
Attempts 3/4 (now) - For once, I think I finally have the right people and we are about a month away from getting our prototype online. Whilst attempts 1 and 2 have failed, I know I have learnt from them and hope I am applying those learnings the right way this time around. Time will tell.
As to ideas - yes they are important, but any idea, executed properly, will have a market.