> If it is released as open source, how do you identify potential clients for your services?
I think there's two parts to that. There's more traditional marketing, where you're offering a solution, which just happens to utilise your own open source product, and then there's engagement with existing users who have indicated, through support and discussion channels, that they're interested in the product but need something more.
> Products released for free start several disadvantages - the user has low expectations for value
To an extent, expectations can be managed. In my experience, a professional-looking web site with well-written tutorial and reference material can make a big difference to the initial impression.
> support costs are unfunded, and the loose relationship between the developer and the user makes it difficult to have long insightful discussions about the user's needs.
But is that not mitigated by the offer of paid support? Then support costs are funded, and there is a stricter relationship between vendor and customer. Is that much different to the relationship with a customer you've actually sold the product to?
> The last question is, are you scratching your own itch as a developer with this project, or is it a startup idea?
It started out as an itch while working for a previous employer, but it wasn't scratchable there. So now it's a startup idea.
We know what product we want to build, we're just not sure what kind of company we want to build around it. As it's still in development, we don't have to make the decision yet, but it's something we need to think about along the way.