According to comScore, the research firm, social networks currently reach 82% of the connected community aged 15 years old and above, equating to 1.2bn people worldwide.
The company also reported that the category took approximately 19% of all time spent on the web in October 2011, measured against 6% for March 2007.
By market, some 98% of the firm's US panel had signed up to these sites, matched by the United Kingdom and Spain. Brazil followed next with 97%.
Elsewhere, penetration stood at 96% in many other countries, including Argentina, Colombia, Mexico, the Philippines and Turkey. Japan, by contrast, logged 58% and China scored 53%.
The average user in Latin America dedicated 7.6 hours to these platforms in October, ahead of 7.3 hours for Europe, seven hours for North America and just three hours in Asia Pacific.
Within this, the typical audience member in Israel committed 11.1 hours to social networks, bettering Argentina's 10.7 hours, Russia's 10.4 hours and Turkey's 10.2 hours.
At the international level, women spent 6.5 hours using social media during October, a total hitting five hours for men.
While 15-24 year olds predictably displayed the strongest uptake on 84%, this figure now stands at 80% or more for all age-groups, with the over-55 year olds generating the fastest growth rate of all cohorts.
More specifically, Facebook had a 55% penetration across the entire social networking audience, accounting for roughly 75% of time spent on these sites, and 14% of all time spent online.
Microblogs have also gained in popularity, as Twitter saw a 59% expansion in user numbers to reach 10% of netizens globally. Sina Weibo, a Chinese microblog, enjoyed growth of 181%, and Tumblr was up 172% on an annual basis.
"The emergence and widespread global adoption of social networks ... underscores the convergence of the online and offline worlds," said Linda Boland Abraham, comScore CMO and EVP, global development.
Data sourced from comScore; additional content by Warc staff, 23 December 2011