Analytics company iStrategyLabs recently examined the demographics stats from Facebook’s Social Ads platform, and found some extraordinary results. In short, Facebook’s userbase, as a whole, is getting much older very fast.

The Numbers

Between January and the fourth of July 2009, the overall number of Facebook users between 18 and 24 years of age grew only 4.8%. In comparison, the number of users aged 25 – 34 grew 60.8%; the number of users aged 35 to 54 grew 190.2%, while the number of users older than 55 years grew a tremendous 513.7%!

Most of the users (20.3 million, or 28.2% overall) on the site belong to the 35 – 54 age group. The 18 – 24 group is now in third place with 18 million (25.1%) users. And during the six-month study period, the number of users in the 55+ group grew from 950,000 to 5.9 million.

Getting Personal

While there are obvious implications for advertisers in terms of whom they are trying to reach on Facebook, the phenomenon of shifting demographics took on personal significance in light of having recently attended my 35th college reunion. The ramp-up to the June event coincided exactly with the term of the iStrategyLabs study. And my experience as a participant in that event closely paralleled the meteoric rise in usage of Facebook among my 55+ cohort.

In January, an initial call to participate in a class Facebook page, and to connect to other potential reunion attendees went largely unheeded…”What’s a Facebook?” By March, various affinity groups (e.g., fraternities, teams, clubs) were starting to recruit classmates using Facebook as the vehicle, encouraging others to join and to submit pictures of themselves in their virile youth. In early June, people who had never had experience with social media were creating Facebook accounts, posting photos of their children and grandchildren (!), and making plans to meet on campus. After reunion, there was a seismic glut of new pictures, posts about shared experiences, and promises to “never lose touch again!” All that in six months.

So if 55+ is officially the new 25, can Boomer Tweetups be far behind?