Rightmove saw over 500,000 visitors on Christmas Day itself but more than 1.3 million visits on December 26, the company said and this rose to more than 2.2 million by the first working day of the year.
With such a captive market -- potential buyers stuck with relatives looking for online distraction from the onslaught on mince pies -- sellers who delay putting their houses on the market until January will miss or delay exposure to this audience of potential buyers, Rightmove said.
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"Sellers who wait until after the Christmas break to get on the market will miss the wave of activity from festive browsers who start their search even before the turkey is finished," Miles Shipside, Rightmove director and housing market analyst, said in a recent note.
"Analysis of Rightmove traffic data shows that buyers are busy online over Christmas. There are nine days of holidays, starting on Christmas Eve, when people have time on their hands to window shop for new properties from the comfort of their own home, often testing out their new tablet and smartphone gifts in the process," he said.
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"While sellers may not want to be bothered by having viewers in the house over the holiday break, it makes sense for prospective buyers to be able to look online, whet their appetite and contact the estate agent to take it further in the New Year."
Shipside recommended that prospective sellers to take advantage of these "festive surfers."
Liam Bailey, global head of research at Knight Frank, said that the Christmas property selling season was a particular feature of the London property market, which remains the most expensive region for house prices.
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Prices in the capital are now 31 percent above their 2007 peak, according to Nationwide's latest House Price index, with the price of a typical London property just above £400,000.
"Looking at the central London market, before the 2008 downturn there was a significant shift away from the traditional spring [buying] season," Bailey told CNBC.
"With City bonuses becoming ever more important in driving market performance, this meant that as the calendar year came to a close, those in the finance sector began to calculate their bonus and started searching for property through December."
"This trend has weakened somewhat but it is a still a feature of the London market – outside of London, the traditional spring selling season is still a fixture of the market," he said.
- By CNBC's Holly Ellyatt, follow her on Twitter Read More@HollyEllyatt.