The average Facebook user who has spent time on the website in each of the last 12 months has been logged on for more than 70 hours, according to the latest Nielsen Online research.
Research from Nielsen also indicates that Facebook was easily the most popular social networking site in September 2009, accounting for 75 per cent of the total amount of time people spent on social media websites.
Over the last year this figure has grown 12 per cent, the market research group states.
Additionally, some 31.3 million Britons visited at least one of the top 75 social media sites during the course of September.
Nic Howell, deputy editor of digital media industry publication NMA, the magazine that commissioned the research, told the Telegraph: "Not only are Britons investing their most precious resource - time - in Facebook, but, according to Nielsen, the site has increased its audience by 52 per cent year-on-year."
Adopting real-time features that are similar to microblogging website Twitter has helped contribute to this increase in popularity, he added.
