Social book-marking website, del.icio.us (pronounced delicious) has seen traffic grow two-fold in the past 8 months, garnering an audience with a higher than average income and education, according to a just-released study.

Internet market research firm, Hitwise Intelligence, released data on Thursday afternoon detailing market-share growth of del.icio.us in the United States.

The site experienced 122 percent growth in traffic from January 2006 to July 2006, more than doubling since January of this year. This ranks the site 6,793 among all websites in the U.S, Hitwise said in an official brief.

Del.icio.us, which Yahoo! puchased in December of 2005, follows an emerging trend of Web-2.0 websites where user interaction and community involvement is as important as content. The site allows its users to bookmark pages or articles they encounter on the internet, storing it for later use, and also sharing it with other users.

Social-Networking sites like Myspace and Friendster also follow this paradigm, and have seen phenomenal growth, but del.icio.us attracts a much more affluent audience, Hitwise reports.

Over 40 percent of visitors to the website have been between the ages of 24 to 34, with a large skew towards users with incomes above $100k per year.

LeeAnn Prescott, Hitwise researcher, stated a majority of del.icio.us users fall within the Urban Uptown, and Elite Suburb demographics. Sampling over 10 million U.S internet users, Hitwise discovered nearly 36 percent of those visiting the site made between $100k to $150k each year, compared to 13 percent of the online population.

Del.icio.us users are a more sophisticated breed of web power user, Prescott conlcuded.

Yahoo U.S.