If you're anything like me, the title "Will it fly?" immediately made you think of Will it blend?. Well clear your head of any marketroid type promotion because this is serious talk! Ev Williams, co-mastermind behind Blogger and Twitter, has written a brilliant blog post about how to evaluate if a new product idea idea is going to work. He's developed a seven point metric which you can use to pretty quickly decide whether you're barking down the right track:

1. Tractability: How difficult will it be to launch a worthwhile version 1.0?
2. Obviousness: Is it clear why people should use it?
3. Deepness: How much value can you ultimately deliver?
4. Wideness: How many people may ultimately use it?
5. Discoverability: How will people learn about your product?
6. Monetizability: How hard will it be to extract the money?
7. Personally Compelling: Do you really want it to exist in the world?

He's done a great job of explaining each of the seven points and uses a whole bunch of real world examples (e.g.: HotOrNot is deeper than you think, Dogster is wider, etc.). His own answer to number 6 surprised me in that Ev feels Twitter will be more monetizable than Blogger was. I'm a big fan of the service and use it regularly (find me here), and I can't wait to see what plans Ev and Biz have for it, but it's not very obvious how those plans involve making money.

If you're developing a new product — or even just thinking of doing so — do yourself a favour and read the post to get a sense of where you stand. It's obviously not gospel (and sometimes the best ideas come out of left field and can't even be charted on existing metrics), but it's a really good step further down the road and will help you prepare for some of the questions investors are likely to ask if you go in that direction.