I built my company solo for about 1.25 years, got a cofounder for half a year (who then quit for a company who could pay more), so I'm back to being solo again on my company WeddingLovely. http://WeddingLovely.com was built entirely by myself and there are also five other vendor directories (http://WeddingPhotoLove.com and others). There's also a wedding blog at http://WeddingLovely.com/blog/ that I maintain and post 2-3x daily.

Being that I continue to build, market, and grow my company while solo (revenues going up every month), I'd say I both came very far as one person and still have much more to go before I hit the end. Don't let imaginary limits discourage you. :)