U.S. online retail sales increased a strong 51 percent in 2003, as vendors on average improved their bottom line, according to a survey conducted by Forrester Research on behalf of Shop.org, the Internet sales division of the National Retail Federation.

It was also the first year in which U.S. online retail sales exceeded $100 billion, reaching $114 billion. That represents 5.4 percent of all retail sales.

Read more: PC World.