Has Social Commerce Found Its Time?

In the late 1990s, Paul Allen tried to take on Amazon.com with Mercata, an online venture in which consumers could get discounts on goods by buying in bulk. The company lasted only a couple of years before closing its doors. Since then, the idea of collaborative buying groups has undergone a revival, particularly in China. And now Rick Braddock, a veteran of both Priceline and FreshDirect, is backing a new U.S. venture with a similar business model, called Joinem.

Mr. Braddock argues that previous collaborative buying efforts didn’t have the benefit of social media. And while profit margins can be thin—Joinem expects a margin of 10 percent—he says the costs of acquiring customers will be low because of viral sharing of the idea.

Joinem is one of several e-commerce companies he is backing. Others include data analytics firm Gravy and fresh food delivery site Zaycon Fresh, all of which he sees as benefiting from the growth of social media and mobile.

With a business career that spans 50 years, Mr. Braddock has a perspective far longer than most other tech investors. He talked to The Information about his new e-commerce endeavors and the current state of tech investing. Edited excerpts follow.