Nearly five-year-old Tumblr recently released its 2011 stats, and it’s looking like last year was the company’s best yet, with 900 percent global growth since 2010, mentions on both the Daily Show and Jeopardy and a ninth language (Polish) added to its repertoire.

With that kind of growth, it’s no surprise that an increasing number of brands are tapping into Tumblr’s uniquely engaged community.

Described as a content network by its 25-year-old founder, David Karp, Tumblr has settled comfortably at the intersection of design, content and social media.

Tumblr founder David Karp. Image by Scott Beale, via Flickr.

Tumbleloggers (as they’re known) can display and share 140 character posts, lengthy blog entries, high-resolution pictures, personal charts and lists, quotes, songs and videos, in one customizable space.

While continuing to foster a unique and dedicated user base of over 13 million visitors, Tumblr has avoided being lumped in with social media platforms like Facebook and Twitter by maintaining its focus on visually rich content.

Meanwhile, Tumblr’s strong social component and easy sharing have made it a more popular blogging platform than WordPress, which it now surpasses in numbers of blogs.

The community

Tumblr’s community is considerably younger than many of its competitors. Where recent statistics have pegged the average Facebook and Twitter users as being 38 and 39 years old, respectively, 50 percent of Tumblr’s users are under the age of 25.

To reach this young, international community, Tumblr has begun sponsoring local meetups around the world. On a monthly basis, tumbleloggers are receiving up to 9,000 nametags and 3,000 Tumblr stickers from the platform’s community organizers in order to facilitate these Tumblr-centric events.

In June, the Tumblr team even received a happy birthday YouTube serenade from a few hundred Brazilian fans meeting up for the platform’s biggest get-together yet. Tumblr’s community was also a driving force behind this winter’s mass online protest against a pair of proposed anti-piracy bills in the U.S.

What’s in it for brands (and what brands should be on it)

What all this means is that Tumblr provides brands with an opportunity to engage a young, media-savvy community with smart, relevant content.

But it’s not a perfect match for everyone. The demographics, for one thing, indicate that marketers should focus on brands that already resonate with the Tumblr community. So life insurance companies, stay away.

It’s also worth bearing in mind the site’s layout. Like upstart Pinterest, it’s all about the visuals and snappy content: Think Twitter plus pictures. This makes the platform perfect for companies that regularly roll out new products or content, namely: broadcast media outlets, magazines, record labels and fashion brands.

J.Crew's tumblog

Take J.Crew, for example. Marketers found a way to make the retail brand’s photogenic merch feel right at home on Tumblr. The brand’s tumblelog has secured a faithful following by inviting followers to tag along with their favourite designers on “inspiration trips” to Paris and Italy while listening to the Brit-pop playlists that fuel their creative genius.

Unlike Facebook, Tumblr is not a one-size-fits-all social network. But as J.Crew can attest, if you’re targeting the cool kids, it’s a shoe-in for success.