Despite the onset of the summer holiday season, when media consumption decreases as people leave homes and offices, the total UK online population in July reached its highest-ever figure - 31.8 million unique visitors - according to comScore's World Metrix audience ratings service, reports MarketingCharts.

Google was the UK's most-visited property, attracting 28.2 million unique visitors - an 89 percent reach of the total online population. It was followed by Microsoft Sites, which attracted 26.9 million unique visitors - a reach of 85 percent.

Online retail properties eBay and Amazon also ranked among the UK's largest sites, with 22.1 million and 12.5 million unique visitors, respectively.

Coinciding with the school summer holidays, cinema site Odeon.co.uk was the top-gaining property in July. The site grew from 1.8 to 2.6 million unique visitors - a 49 percent increase.

Next was the fastest-growing site among three holiday and travel properties, lastminute.com, which grew 30 percent to reach 5.2 million unique visitors. Cheapflights Sites, a flight and travel price comparison property, grew 22 percent to 2.8 million unique visitors, and First Choice Holidays PLC grew 19 percent to 3.6 million.

Several online retail sites also experienced growth in July:

• Helped in large part by the launch of the outlet's new catalog, traffic to the NEXT Group property grew 18 percent to 3.9 million unique visitors.
• Play.com and Dixons Stores Group experienced similar growth, reaching 4.8 million and 4.7 million unique visitors, respectively.

Social-networking site Facebook.com proved to be the UK's third fastest-growing site in July, increasing traffic 26 percent to reach 7.6 million unique visitors. The site has grown 366 percent since the beginning of the year and has become the UK's third-largest social-networking site, behind Bebo and MySpace.

"The success of travel and holiday sites mirrors the seasonal trends in the offline world, with July being a popular month for holiday, retail and entertainment sites," Bob Ivins, EVP of International Markets at comScore, said.

"However, with the weather in the UK being so poor this summer it's clear that - for domestic recreation activities at least - people have been surfing the internet for indoor entertainment, hence the growth in traffic to cinema site Odeon.co.uk."