The situation goes like this. Lots of excellent, capable people have great ideas for new software products. They are bootstrapping their venture, so they look for a developer who wants to give some time up front and receive a fair (let's assume fair) share of the rewards once the product becomes successful.

The question is: as a developer, how do you know which of these products (I get about one tempting enquiry a month from what sounds like a real person who isn't building a social network) is a good bet?

For my own products, that's easy. I know what I want to build and while it's tough to be customer, project manager and developer all on my own, I can at least give it a shot. I am self-employed and my products get time scheduled in just like all my other projects do - well, unless there's more interesting paying work to be had, in which case they tend to slide!

But what about those other excellent business people, who understand their market, have a great idea for a product, and are confident they can bring in enough paying clients to make the whole thing balance within a couple of years? They should be able to launch their products too - but of course they need some technical skills on their team to do so.

For me, as a developer, I would love to get involved in some new ventures. I enjoy building things that other people need, and as a freelancer I'm flexible enough to take on some side projects that won't pay me back directly. I've been approached by perfectly sane-sounding local people who already run viable businesses and are looking to offer software products alongside those. They know their market, their domain, and they know what they want. So far, I've got enough work of my own that I haven't been sure enough to take the risk when it came past ... but will I ever know when to jump in and get involved?

What are your thoughts? Have you joined in building something new with people you haven't worked with before? On what kind of basis? Are these kind of projects ever worth picking up? Perhaps more interestingly, have you been burned and if so, what would you say were the warning signs now you have some hindsight?