When I started my first company some years ago I placed all my focus on creating a great offering, but almost no effort went into sales and networking. Needless to say that it took an incredibly long time to get off the ground - 6 years in fact.
During that time I learned a lot about how business works, and my focus has shifted almost completely onto sales, marketing and networking.
Nowadays, a good idea with a quality product backed by excellent service is the bare minimum required to succeed. Because there is so much competition (especially online), what sets companies apart these days is how effectively they can network and promote themselves.