Brian Solis, founder of Silicon Valley PR and new media firm FutureWorks, was trying to figure out why people are spending less time on Twitter.com than they were last year, his theory being that more people were migrating from the microblogging service's web site to third-party clients. He writes:

I asked my good friend Dan Zarrella, author of The Social Media Marketing Book, if he could help me run the numbers to see exactly what the world of usage looks like at Twitter.com compared to the mobile and desktop clients that are becoming increasingly pervasive.

So last month they tracked the publishing source of more than a half-million tweets. Crunching the numbers, Solis came up with a ranked order of clients and apps used for publishing to Twitter.

The first thing you notice, of course, is the vast number of Twitter tools out there (check out the list in Solis's post). Increasingly pervasive, indeed. But when you start looking at market share, you see only 12 higher than 1 percent. Here are the top five:

Web,40.945%
API,11.6418% (custom applications, scripts or bots)
TweetDeck,6.635%
UberTwitter,4.288%
twitterfeed,3.9538%

As you can see, usage of Twitter.com remains the leader with nearly 41 percent. (I don't have earlier numbers, so we can't look at trends.) TweetDeck, which everyone and their web-savvy mother swear they love, has 6.6 percent. And while twitterfeed, the scourge of Twitterians who want to "keep it real," is No. 5, the auto-tweeting service is responsible for just one out of every 25 tweets.

On the other end of the list, if you add up the market share of the bottom 20 clients and apps, the total comes to 0.3 percent. It'll be interesting to see how much longer Twitter clients and apps can proliferate before the market consolidates.