"Old school" enterprise sales meant hiring an army of field salespeople. It meant on-site visits, and pitching directly to the CIO, CFO, CMO, hiring sales engineers to build pilots, negotiate with procurement for months, etc. And all that meant the cost of a sale was high -- often $50,000+ -- which meant that your contracts had better be in the six-figures if you want to be profitable.

That's now how most B2B companies work in 2013. Look at Stripe, Yammer, Parse, Github, or Twilio -- you can sign up directly on their web site, often get started for free or cheap enough that you don't trigger purchase approval. Most of the customers for those companies come in through inbound channels, like blog posts, ads, partnerships, or referrals. And to the extent that they have sales, it's inside sales, primarily working to convert existing, happy users of the product to paying customers.

Chris Dixon has a great related blog post on this: http://cdixon.org/2012/09/24/the-rise-of-enterprise-marketin...