More than 25,000 rock station listeners polled.

A new poll of more than 25,000 respondents/listeners of 79 different rock stations from Jacobs Media says XM and Sirius are now equally popular, but the momentum—largely driven by Howard Stern—is shifting toward Sirius.

Overall satellite radio subscribership increased from 7% in 2005 to 12% in this year’s survey. But when compared to other new media—Internet streaming, iPod ownership and usage, and cell phone applications—satellite radio remains a medium that is still in its infancy.

That's because the majority of respondents still like their radio free. In response to an “agree” or ”disagree” statement—"I will not pay for radio when I now get it for free"—seven of every ten poll takers agree or agree strongly.

The Jacobs poll reveals a dead heat between Sirius and XM—both are tied with 6% each among all respondents. Not surprisingly, men are more apt to subscribe to either service, as are 30-39 year-olds, college grads, and those with a household income of $100,000 and more.

Interestingly, the reasons current satellite radio subscribers selected either XM or Sirius were largely driven by the programming and marketing strategies that each company has employed.

For XM, the top reasons for signing up are the music channels (24%), commercial-free programming (14%), the belief that XM is good while traveling (12%), and because it came with the vehicle that they purchased or leased (11%).

Sirius subscribers, on the other hand, were heavily motivated by the arrival of Stern. Overall, one-third (32%) of those who now pay for Sirius list him as the key factor in their decision. Other reasons include the music channels (19%), and commercial-free programming (12%).

The vast majority of satellite radio subscribers in the survey are pleased with XM and/or Sirius, according to the survey. Seventy-five percent say they’re satisfied or very satisfied, while only 8% express some level of dissatisfaction.

Jacobs’ poll was conducted in Feb. 2006.