A popular topic given Pandora Media's (NYSE: P) IPO yesterday is the impact that the now-more-public music discovery website will have on Sirius XM Radio (Nasdaq: SIRI).

Shares of the satellite radio operator have slipped 20% since hitting a nearly three-year high of $2.44 at the end of May. Surely the buzz and hype over Pandora's debut is weighing on the performance of Sirius XM. Right?

Not exactly.

Sirius XM is a volatile, high-beta investment. The past few trading weeks have been brutal for the markets in general, and Sirius XM has a tendency to exaggerate market movements. Throw in weak auto sales for the month of May and you get a slide that has little to do with what the country's leading streaming website is doing.

Save for a brief spell during the recession-peppered first half of 2009, satellite radio as a medium has gained net subscribers every single quarter since its debut.

Keep in mind that satellite radio and Apple's (Nasdaq: AAPL) iPod were introduced to the public in 2001. Both have been able to grow in popularity over the past decade, even if some see them as competing eardrum magnets. Why should it be any different between Pandora's user-customized playlists and what satellite radio is up to?

Yes, dashboard technology is evolving fairly quickly these days. This is Sirius XM's turf, and the popularity of smartphones is giving drivers new options for audio entertainment in cars with audio input jacks or Bluetooth connectivity. AT&T (NYSE: T) and Verizon (NYSE: VZ) are finally deploying their 4G LTE networks this summer, a move that will help improve audio quality and reduce the buffering that often makes smartphone streaming on the road a deal breaker.

Drivers spend a finite time on the road, so it's a perfectly valid assumption that smartphone owners in high-tech cars may spend less time listening to satellite radio. Will that be enough to bump cancellations higher? I don't think so. Subscriptions are still cheap, and we're still talking about premium content. Even in an ideally connected world where satrad subscribers may begin fancying Pandora playlists over the programmed music on Sirius XM, there are still dozens of talk channels and exclusive music news and interviews that will never work their way into Pandora.

They can co-exist. They have obviously done exactly that for years, which each platform growing to appeal to tens of millions of listeners apiece. The only thing that a hot or cold Pandora post-IPO run will achieve is widen or contract the valuations for the niche itself.

Would you rather buy Pandora or Sirius XM today? Share your thoughts in the comment box below.