It's pretty unusual to be acquired by another startup. It's generally the culture clash, hierarchy and bureaucracy that make acquisition suck for the acquiree. None of that happens when a startup acquires you.
How do you figure? They've established a great business model, have over 50 employees, profitable, and are acquiring other companies. Everything needed to be labelled a success business IMO.
What else would they need to do in order to be pass the start-up mark?
A successful business doesn't mean they're not a startup anymore. Dropbox is hugely successful, but definitely still a startup and its infancy.
Github will remain a startup until they can make a dent in the big boys' bottom line, for example: Perforce.
Github is insanely successful amongst startups and hackers, but has yet to significantly penetrate the enterprise. Hopefully this will change (for us and for them) because their product is a gazillion times better than anything else out there.
