Google+ now second-largest social networking site: survey

In an update of its Global Web Index (GWI), this week UK market research firm Trendstream showed how well Google's strategy of driving users to its social networks was working.

According to GWI, Google+ now was placed at the second spot in the social network pecking order in terms of active users, followed by YouTube, which makes its debut in the index.

According to the report the number of Facebook's active users in December 2012 stood at 693 million, as against 343 million for Google+. GWI does not give the number of YouTube active users, but from the chart it appears to be approximately 280 million.

Given the significant overlap between Google+ and YouTube in terms of users, the two numbers cannot merely be added up to say Google+ is only 70 million active users behind Facebook, but if all active YouTube users were to become active Google+ users it would likely add to the 343 million.

Though Facebook's active users are undoubtedly more active than Google+'s , it needs to be borne in mind that all active user numbers are however suspect, including that of Facebook.

Every action by users while logged as users of a social network can make them an ''active user.''