Back-to-school and the approaching football season helped books, sports and apparel gain a foothold in August says comScore Media Metrics. The new report takes a look at US web activity in the month leading to a list of the top 50 web properties and the top ten categories. Retail book sites were the biggest winners in August with an 11% percent increase of July as folks left the beaches and went back-to-school. While Barnes & Noble continues to close brick and mortar stores,