Bebo cemented its position as market leader with a 63% rise since the start of the year. It registered 10.6 million unique users in July compared to MySpace’s 10.1 million.
Although this is the first time Bebo has topped comScore’s listings, the site has come out top in previous studies by other research firms.
comScore only tracks people aged 15 and above, meaning that much of the user bases of sites such as Bebo and Piczo go undetected.
Facebook recorded by far the biggest leap in user numbers, from 1.6 million to 7.6 million, and remains in third place behind Bebo and MySpace. Hi5 and Faceparty make up the top five sites in the UK, with 1.9 million and 1.7 million unique users respectively.