From the article:
Since 2008, Polaris Venture Partners, a Waltham, Mass., venture-capital company, has opened incubators, called Dogpatch Labs, in Waltham, New York and San Francisco.

Another benefit of incubators is that their tenants can exchange ideas and advice with other budding entrepreneurs. “If you need help with something, like understanding how to advertise on Facebook, you can go to others in your space,” says David Ambrose, whose start-up, Scoop St., an online collective-buying service, moved into Dogpatch Labs’ New York incubator in January.

Mr. Ambrose’s company must move out by June, as residency there is limited to six months. The incubator currently provides 15 start-ups with as many as five desks per company, Wi-Fi access, conference space and snacks.