MediaPost.com is reporting results from a recent study by Anderson Analytics showing that Twitter has become more popular than LinkedIn among social network users in the United States. Aside from posting tweets, Twitter users tend to blog frequently. Another interesting finding: those who belong to a social net are four times more vocal about products and services than those who don’t. More than 20% have their own blog, many of which are about social causes. Anderson Analytics says these consumers make good evangelists for brands.