Facebook's built-in e-commerce offerings aren't delivering strong results for most of the brands using them, in part because the site's users are usually trying to relax and socialize, not make purchases, Phillip Rooke writes. Still, marketers shouldn't give up on Facebook as a sales tool, he argues. "[W]hile they currently aren't making many purchases, many Facebook visitors happily talk about brands. ... It's ripe for a well-designed ecommerce approach," Rooke writes.