Building a repeatable and scalable business model around a plugin is very possible. As with any start-up that hopes to see it past three birthdays, a strong initial ( almost manic ) focus on a building a good MVP to share for validation by users is a great starting point, something that's very possible with plugins. I agree with Jeff, thinking like a business (and by extension owning the "We are a business" label ) is critical. I disagree slightly with Miroslav - the issue might not be egos; it just might be that, like all start-ups (even outside WordPress), finding a good pricing model is a very sticky issue.