Satellite radio is the real deal.

On Monday, we learned that Sirius XM Radio (Nasdaq: SIRI) closed out June with roughly 22.9 million subscribers. As iffy as consumers may feel about this dicey economic recovery, we're talking about a platform that has tacked on a million more accounts than it has lost through the first half of the year.

There may be more than a few company-specific concerns, of course. With the equivalent of 6.5 billion shares outstanding -- more stock than only a handful of companies -- we're talking about a market cap of $13.5 billion. Sirius XM is still susceptible to the ups and downs of the automotive industry. Its largest investor is trying to wrestle away de facto control.

However, there are solid reasons to hold on here. Let's go over a few of them.

1. Raising guidance is the norm for Sirius XM
There was only one time that CEO Mel Karmazin had to eat his words. It was late 2008, and both the economy and automotive industries were teetering. Sirius XM's rosy projections just weren't happening, so Karmazin hosed them down.  

The fallout wasn't pretty. Sirius XM went to shed net subscribers during the first and second quarters of 2009, but that's the only time satellite radio as a platform has closed out a quarter with fewer subscribers than when the period began. It was also the only time Karmazin had to lower his company's fiscal outlook.

It's been smooth sailing since then, and a constant through the past three years has been that whatever Karmazin projects in terms of subscriber, revenue, and cash-flow growth won't be enough. It'll all be revised higher a quarter or two later.

Even Monday's raised targets -- calling for 1.6 million net subscriber additions and $3.4 billion in revenue -- seem woefully conservative. Auto sales have been strong, soaring 22% last month. Even Ford's (NYSE: F) 7% increase -- a laggard relative to its rivals -- drove by the 4% uptick that analysts were expecting. Brisk car sales translate into self-pay customers as their free trials run out. A little less than half of new-car buyers continue to pay for satellite radio after their free trials run out, but that essentially means Sirius XM can make up for it in volume.

Between strong auto sales and January's rate increase, don't be surprised if subscriber and revenue targets continue to move higher during the latter half of the year.

2. Liberty Media is a validator
John Malone's Liberty Media (Nasdaq: LMCA) had to wait three years after receiving its 40% preferred-share stake in Sirius XM to make any kind of move. The holding company didn't wait long, quickly moving to petition regulators for control of the company as it boosted its effective stake to 46.2%.

Why would Liberty Media be moving so quickly? Why be a buyer rather than a seller? Could it be that Malone and his savvy cast of puzzle builders at Liberty Media know that Sirius XM will be worth more in the future?

3. Internet radio is more of an opportunity than a threat
Cynics have been quick to call satellite radio a transitory technology, pointing to the rise of Pandora Media (Nasdaq: P) and other streaming services as the future.

There is certainly merit to the argument that streaming is an explosive industry. Pandora's now serving more than a billion hours of music a month. Spotify has exploded on the scene since washing ashore last summer. Clear Channel's (NASDAQOTH: CCMO.PK) iHeartRadio has landed 10 million registered users since its star-studded relaunch last fall.

However, Sirius XM is more popular than ever. Whether you prefer to consider the rise in the satellite-radio giant's subscriber base by more than a million over the past six months or by nearly 1.9 million over the past year, it's clear that the platform is still gaining ground despite the booming smartphone and online streaming market.

As Sirius XM improves its own premium streaming product, it will be a beneficiary of this trend.

Running of the bulls
I remain bullish on Sirius XM's future. It should come as no surprise that I'm promoting the CAPScall initiative for accountability by reiterating my bullish call on Sirius XM for Motley Fool CAPS.

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