Genuinely curious here. To narrow it down a bit, let's talk businesses who primarily operate on the web or through a mobile app.
It just seems that outsourcing the core of your business is a strategy that's destined to fail.
You need to be able to pivot, and fill in the blanks as you go along. Most freelancers and shops don't give you this option, or at least not at a reasonable cost. It feels like most businesses would be much better off hiring someone and giving that person a piece of the business as part of the deal.
Terralien does ongoing development work for six businesses for which we built the original technology. Their degree of success varies, but they all have in common that they're successful enough to have persisted 1+ years and are continuing to make progress. All of them rely on software for their core business to some varying degree, but in none of their cases is the software itself rocket science. It may be moderately complicated and there may be a lot of it, but a good hacker could pick it up without completely derailing the project in the meantime.
On the flipside, Terralien had one very tech-heavy business that we got off the ground, after which they brought development in-house in the form of a developer working for equity. It made total sense for them, since they were doing algorithmic work in the energy space so their technology was in a way "rocket science" and they needed to have that close.
I think anyone considering outsourcing the software build for their startup should look for a freelancer or devshop that is ready and willing to serve as their CTO for the long haul. You want a shop or an individual that understands technology as a tool that should serve the larger business purposes, and not an end in itself. That's the way we try to approach it at Terralien, and it seems to be working really well for our clients.
I think some of the difficulties I've had in these type of projects stems from the customer not knowing where they want things to go / not having thought things through.
In this situation they seem eager to bounce ideas, which is great, but once those new ideas start affecting deadlines and budgets, the relationship can get tense.
IP doesn't automatically confer..