Social media is the fastest-growing source of traffic to online retail sites–but visitors from Facebook or Twitter have a lower conversion rate than those arriving on a shopping site via a search engine, according to a new study released by e-commerce personalization engine RichRelevance. The company analyzed more than 200 million August 2011 shopping sessions on major US retailing sites to understand trends in online shopping behavior, and found that Facebook traffic to online retailers increased 92% from August 2010 to August 2011. Read →