Politics, careers and real estate dominated the search charts for US web users during January, according to figures from comScore.

The research firm's monthly analysis of US consumer activity at top online properties showed that the official start of the US tax season sent Americans online in droves.

The 'tax' category rose 202 per cent to more than 23 million visitors, making it the top-gaining category in January.

The IRS.gov website led with 12.5 million visitors (up 181 per cent), followed by TaxACT with 5.8 million visitors (up more than 1,000 per cent) and H&R Block with 5.3 million visitors (up 312 per cent).

Politics also jumped as the Presidential primaries kicked off, gaining 65 per cent to 13.8 million visitors as Americans went online for news and opinions and to visit candidates' websites.

BarackObama.com led with 2.2 million visitors (up 429 per cent from December), followed by HillaryClinton.com with 1.1 million visitors (up 202 per cent).

On the Republican side, MikeHuckabee.com attracted 937,000 visitors (up 96 per cent) while JohnMcCain.com saw 596,000 visitors (up 261 per cent).

The 'career services and development' category experienced a 31 per cent gain for the month as many Americans re-evaluated their career situations with the advent of the new year.

This category was led by CareerBuilder.com with 24.8 million visitors, followed by Yahoo HotJobs (17.4 million) and Monster (17.1 million).

"The new year is a time for Americans to reflect on the past year and plan for the coming year, whether searching for a new job, a new residence, or preparing for the tax season," said Jack Flanagan, executive vice president at comScore Media Metrix.

"There was also a huge surge in activity at political content sites as the Democratic and Republican Presidential primaries kicked off with the Iowa caucuses in early January."

Concerns over a shaky property market, along with those resolving to move in 2008, precipitated a 28 per cent gain to 42 million visitors to the 'real estate' category in January.

Move Network led with 10.1 million visitors (up 49 per cent), followed by Yahoo Real Estate with 4.6 million visitors (up 50 per cent), and Rent.com with 3.5 million visitors (up 51 per cent).

Yahoo Sites continued to lead as the top property overall with more than 138 million visitors, followed by Google Sites with nearly 135 million visitors and Microsoft Sites with 119 million visitors.