I want to pay...
I guess that firms need to pay for a product otherwise it is worthless for them. OpenSource sure, but I want to pay a license for it to someone, because that is what I have been doing for so long, and OperSource Solutions works so I have to pay.
Under this scenario, you need to create a "product" to be sold, since it is OpenSource you need to disguise it, errr new features on you product, not disguising sorry. And provide something like an update support agreement just to say you need to upgrade, so I can renegotiate the contract... And it is business as usual for most firms.
And yes, the risk is adopt, embrace and extend...