We're now less than 24 hours away from Sirius XM Radio's (NASDAQ:SIRI) third-quarter report. Since it's one of the market's most heavily traded stocks in terms of sheer volume, speculators are lining up on both sides of the report.

Is this the report that validates Sirius XM as a cash-flow positive media giant? Or is it another step down for a platform that may have peaked last year?

Hold your love letters (or battering rams) for the company. Let's go over three of the meaty questions that should be answered tomorrow.

1. Where are the subs?
After shedding net subscribers during the first and second quarters, it's time once again to take roll call.

There are a few things working in Sirius XM's favor here.

  • The trend itself has improved, since closing out the second quarter with 185,999 fewer subscribers is better than the 404,422 listeners it lost during the first three months of the year.
  • Between Ford's (NYSE:F) bullish quarterly report and the successful "cash for clunkers" campaign, there are signs of life in the automaker industry. This is arguably Sirius XM's best source for new accounts.
  • The economy appears to have turned, and other subscriber-based consumer services are bouncing back. DISH Network (NASDAQ:DISH) turned positive during the second quarter, leaving Sirius XM, TiVo (NASDAQ:TIVO), and Time Warner Cable's (NYSE:TWC) flagship video service as the only heavies losing subscribers.

Two months ago, my best guess had Sirius XM shedding 80,000 subs, as an uptick in churn over recent rate hikes and new fees eat into the new bodies. I opened up the stage to other crystal ball watchers, and I'll crown a victor among the dozens of predictions tomorrow.

2. How is the bottom line holding up?
Last year's merger between Sirius and XM has created several cost-saving possibilities, above and beyond the typical synergies associated with major deals where overlapping redundancies are eliminated.

Subscriber acquisition costs have diminished as Sirius XM can market satellite radio with a unified front, instead of the two companies having to attack one another. As the only game in town when it comes to satellite radio, Sirius XM will have a little more leeway with its automotive partners and on-air content when contracts come up.

The extent of the cost savings finds Sirius XM ramping up its projections for adjusted operating profits in 2009 -- from $300 million to $350 million to $400 million -- over the past year, despite subscribership shrinkage.

A healthy quarter, enhanced guidance, or a clear path of conviction to actual profitability will go a long way toward offsetting any potential weakness in its subscriber tally.

3. How about them Apples?
There was a lot of hype behind June's release of an official streaming application on Apple's (NASDAQ:AAPL) App Store. Excitement died down after it was revealed that Howard Stern wasn't available on the app. It also irked satellite subscribers to learn that they would have to pay extra for streaming, perhaps spoiled by the Netflix (NASDAQ:NFLX) couch-potato subscribers who can stream films online at no additional cost.

Even CEO Mel Karmazin deflated those hopes during the company's conference call in August. He didn't reveal the actual count of App Store subscribers but warned that it's not "a significant number."

That was then, though. The third quarter is the first complete period in which the premium streaming program was available. It would be great to hear some hard numbers here, and at least a little more color as to the significance of online subscribers will do.

Come back tomorrow when we'll break down Sirius XM's report, discussing the answers offered to these three defining questions.

Apple and Netflix are Motley Fool Stock Advisor recommendations. Try any of our Foolish newsletter services, free for 30 days

Longtime Fool contributor Rick Munarriz is a subscriber to both Sirius and XM. He does own shares in Netflix and TiVo. He is also a member of the Rule Breakers analytical team, seeking out the next great growth stock early in its defiance. The Fool has a disclosure policy.