You're right - for most small teams. For companies with tons of money and resources, probably a bit less so, as the barrier to entry becomes bigger and bigger.

You're right - for most small teams. For companies with tons of money and resources, probably a bit less so, as the barrier to entry becomes bigger and bigger. That, and as Facebook proved time and again, they can afford to just copy you from scratch. For SAAS products, what I typically try to do is open source the libraries, but not the product. So, for example, if I were to write something simple that checked a device, and sent an email, assuming neither library existed, I'd open source the device api library and the email library, but not the product that uses the two in conjunction. I think it's a good balance.