Traffic to online classified advertising sites has increased almost 50 per cent in the past 12 months, new research reveals.

Statistics released by web monitoring firm ComScore show that 37.4 million internet users visited consumer-to-consumer selling sites in July, accounting for almost 22 per cent of the total internet population. 

Social advertising site Craig's List dominated the category, attracting 13.8 million visitors in July 2006 representing a 99 per cent increase on the previous year. 

Trader Publishing Company ranked second with 10.2 million visitors, up 15 per cent, followed by AutoTrader which ranked third with 6.4 million visitors, up 14 per cent. 

"While online classifieds are not new, it appears that internet users are really beginning to catch on to this phenomenon," said senior ComScore analyst Andrew Lipsman.

"With nearly 50 per cent growth in the past year, online classifieds are growing at a rate that surpasses most other categories.

"As the category leader, Craig's List has clearly impacted the way in which new and traditional media companies approach the classifieds business."

The study also found that online classifieds are more popular with young adults and higher income households.

Analysis of the category revealed that young professionals were more likely to visit online classified sites.

People between the ages 25-34 and those living in households making at least $100,000 annually were each 23 per cent more likely than average to visit such sites.