Is your brand on Tumblr yet? If not, maybe it should be.

A recent comScore report shows that Tumblr's incredible growth during 2011 has given it a strong foothold in the world of social media. It turns out that the microblogging site ranks second among all social networks in terms of user engagement and how much time is spent on site. Only Facebook keeps its users on site longer.

Social media is all about networking and shared interests, which plays directly into the strengths of the Tumblr format. Tumblr promotes and allows for anonymous content-sharing and doesn't require users to divulge any personal information on their profiles.

Tumblr seems to be positioning itself as a very distinct alternative to Facebook, and this could greatly benefit the social network in the future, as evidenced by the fact that its numbers continue to grow at a steady pace.

While brand adoption of the platform has been lukewarm to say the least, it would seem that if users are starting to spend more time on Tumblr than other social networks – most notably Twitter and Google Plus – then we may start seeing more brands establishing their presence on the site.