This has certainly been an interesting year for little ‘ol Twitter. Growth has exploded, celebrities have been joining in droves and Twitter continues to expand their feature set in an amazing effort to make those 140-character tidbits all the more valuable. Brands have also noticed the value in Twitter, listening in on the thoughts of millions of people in hopes of not only improving customer satisfaction, but winning customers over with a personal touch. Fellow Twitterer Dave Peck experienced this earlier this year when Southwest Airlines tried to help him out after getting stuck in Austin.

How appropriate, then, is the graph below that shows @SouthwestAir as the most active airline on Twitter, based on the number of monthly tweets from January to September of this year.

I decided to put this graph together after reading @BrianSolis’ post on airline activity in August. Curious what the rest of the year looked like, I pulled some data from TweetStats and decided to try to represent the data in a StreamGraph, courtesy of Lee Byron’s awesome StreamGraph work. This is my first attempt and could certainly use a little tweaking, but the trends in airline activity over the course of the year are readily apparent.

In addition to simply seeing how active airlines have been over the past year, the graph also shows the overall number of tweets for each airline (font size) as well as the most active month for each airline (placement of their Twitter username). There are some airlines not marked on the graph as their activity is insubstantial.

Also of note is @FlyHawaiian, whose usage of Twitter increased tremendously in September.

Detailed stats for any of the airlines can, of course, be found on TweetStats. ;)