As Twitter goes mainstream, is music as big a driver of Twitter traffic as other topics? Judging from the number of times SXSW was used in Twitter messages over the last few weeks, it's clear the technology camp uses Twitter with far greater frequency than does the music camp.

Twitter made a smashing debut at SXSW two years ago. In 2009, during the interactive portion of the conference, SXSW was a popular tag to the point of saturation. Music conference attendees used Twitter as well, but not as often as did interactive attendees. Using Twist, an online tool that graphically shows Twitter tag trends, the difference between the usage of the two groups becomes obvious.

The interactive portion of SXSW, also known as SXSWi, ran from March 13-17. The peak day for the SXSW tag (including SXSWi) was on March 14. On that day, SXSW appeared in 1.47% of all tweets. During the music portion of the conference, which ran from March 18-22, the peak day for the SXSW tag was March 18th with 0.5% of all tweets. The high point during the busiest concert days was on March 22nd with a 0.45% frequency.

So the interactive tweets were three times as great as music tweets. And that's before figuring in how many people actually attended SXSW during each week. It's safe to say there were far more people at SXSW during music week, which would give interactive week a huge per-person tweet edge.

Determining approximate per-person tweets for each portion of the conference, however, is difficult. The about page says the music week has nearly 12,000 registrants while the interactive and film combine for about 11,000 registrants. For music week, 4,000 wristbands were sold and thousands - if not tens of thousands - more showed up for free events. The Fader tent alone reportedly gave out 17,000 wristbands to its four-day, unofficial SXSW party.

SXSW does not release attendance figures for each event, though it has revealed that more than 9000 registered in 2008 and the ten-day attendance that year was 149,000.

Beyond the nice-to-know statistical comparison, there are marketing implications here. While some technologists and marketing experts argue Twitter is a mandatory marketing tool, its usefulness depends on the particular artist and the Twitter habits of its followers. Just as there is a variance in usage in interactive and music weeks, Twitter adoption rates will vary by artist, genre and fan demographics. An artist may decide to hop on the Twitter bandwagon, but many fans may not be ready to join in just yet.