<p>In 2013, no company can expect to be taken seriously if it's not on Facebook or Twitter. An endless stream (no pun intended) of advice from marketing consultants warns businesses that they need to "get" social or risk becoming like companies a century ago that didn't think they needed telephones.</p><p>Despite the hype that inevitably clings to the newfangled, however, it's relatively antique tech that appears to be far more important for selling stuff online. A new report from marketing data outfit Custora found that over the past four years, online retailers have quadrupled the rate of customers acquired through email to nearly 7 percent.</p><p>Facebook over that same period barely registers as a way to make a sale, and the tiny percentage of people who do connect and buy over Facebook has stayed flat. Twitter, meanwhile, doesn't register at all. By far the most popular way to get customers was "organic search," according to the report, followed by "cost per click" ads (in both cases, read: Google).</p><p>Custora came up with its figures by analyzing data from 72 million customers shopping on 86 different retailer sites. They tracked where customers were clicking from (email, Twitter, Google, etc.) and what and how much they bought, not just on that visit but for the next two years.</p><p><a href="http://www.wired.com/business/2013/07/email-crushing-twitter-facebook/">Keep reading...</a></p>