A detail of Randy Olson’s stacked area chart of reddit. Fuuuuuuu. Image: Randy Olson

Here's 2006. In the site's early days, Reddit.com was the main attraction, but in February they added the first topical subreddits. Image: Randy Olson

2007. Nerd-friendly subreddits thrive. A celebrity-centric Lipstick.com section is replaced by r/entertainment. Image: Randy Olson

2008. The year of Reddit's "Cambrian Explosion," as Olson puts it. Why? This was the first point Reddit allowed users to create their own subreddits. Image: Randy Olson

2009. The subredditification continues. Olson's not sure what caused the /r/reddit.com spike in the middle of the year. Image: Randy Olson

2010. Olson calls this "the year gamers and porn invaded," partially thanks to an influx of users from the then-recently-defunct Digg.com Image: Randy Olson

2011. The year of the memes. Also the year mods pulled the plug on the catchall subreddit r/reddit.com. Image: Randy Olson

2012. The Reddit of today, dominated by images and other more mainstream, accessible content. Image: Randy Olson