One could describe Tumblr as a combination of Facebook, Twitter and WordPress, yet with more capacity for individual customization. Founded by David Karp almost four years ago Tumblr is an interactive micro blogging platform that enables users to easily post videos, audio, text, social bookmarks, photos, other user’s blog posts and shares it with other followers of the site.

Fast Company reporter Chris Dannen favors Tumblr because of its multimedia friendliness:

“Instead of having to upload things to YouTube, Delicious or Flickr, or create your own WordPress database before posting things, you can put your media directly into Tumblr from your computer or mobile phone. It’s blogging, the way blogging was meant to be.”

In Tumblr, Karp wanted to create a site that was more than just the standard title-paragraph format.

“We allow you to tear out all the formatting and branding, so the community has done things with their blogs that we never imagined,” said Karp. ”Our job has been to make sure they have all the room they need to create an online identity they’re really proud of.”

So-called “Tumblelogs” (a reference for any stream of thought microblog) include text, photos, video, multimedia, etc.  But Tumblr is especially focused on developing new ways for users to post content, and many community followers tell their stories exclusively through video or pictures.

Tumblr’s popularity stems partly from ease of use—it literally takes seconds to establish an account and get started—as well as the stylish feedback systems and customizable templates. One feature which sets Tumblr apart from other social networking sites is the “answer function” which allows users to post questions on follower’s blogs. Simply ending their sentence with a question mark will allow other users to answer people questions.

“Instead of the standard comment box at the bottom of a posting-which incites spamming, flaming, and congested aesthetics – Tumblelogs have a few other options for feedback.  There’s like a button, which lets other users express their approbation, and the ability to follow and be followed by other users; there’s also a “reblog” feature that lets you embed other people’s posts in your blog, as a way of pointing people to stuff you like.  That’s the makings of true Internet virality – in other words, it encourages you to encourage others to add to content,” said Dannen.

Tumblr’s popularity has also been the source of growing pains. In early December, Tumblr was down for more than 24 hours due to “an issue [that] arose with a critical database cluster.” Questions remain as to whether Tumblr is ready to handle the rapid growth of users. According to Social Times, the site had 75,000 users in 2007; today Tumblr receives almost 2 million posts and 15,000 new users per day.

Aside from the technical issues, Tumblr is a great resource to use, especially if your company or organization is targeting specific audiences and/or has predominant multimedia to share.

Read Fast Company’s full article on Tumblr.