Online music maven Pandora Media (NYSE: P) reports fourth-quarter results on Tuesday. Share prices have fallen more than 20% since last year's IPO, though Pandora is singing a different tune in 2012: Shares have bounced 35% so far this year.

Will this report give investors more gains to sing about or will Pandora rickroll Wall Street?

Well, let's see. The company actually has a habit of shocking the Street: Each of its first two reports showed modestly positive non-GAAP earnings while analysts expected small losses. Pandora could hit "replay" on that pattern again as the average analyst looks for a $0.02 loss per share. In terms of revenue, analysts want to see a 74% year-over-year jump to $83 million.

Pandora's management agrees that a loss might be coming up while setting the revenue bar somewhat below Street standards.

The stock started 2012 on rocket fuel but slowed down considerably after media-wrangling rival Sirius XM (Nasdaq: SIRI) published an underwhelming report. Pandora is seen as a potential threat to Sirius but competitive pressure is ramping up below this duo as well: Newcomers like Spotify and Rdio turn their growth dials to 11, not to mention the traditional radio industry fighting back with iHeartRadio. All of these services offer free or ad-supported all-your-ears-can-eat alternatives to Pandora's bread and butter.

Moreover, the elephants are dancing and some mice could get trampled: Google (Nasdaq: GOOG) and Apple (Nasdaq: AAPL) are duking it out with low-cost media services launched in 2011. And just to rub Pandora's face in just how difficult this sub-industry can be, even Big G can't seem to make Google Music work.

That said, Pandora is still attracting millions of new listeners every quarter and revenue seems to scale nicely with the hours of streaming music served.

In the third quarter, Pandora saw 40 million active users enjoying 2.1 billion hours of semi-random music. These are the numbers that need to swell in order to keep investors happy. At the same time, advertisers must be motivated to pay stable or rising spot rates and the company must take care not to blow expenses out of proportion in this stage of rapid growth. And stock-based compensation expenses are jumping as management shifts some payroll costs onto the backs of common investors.

That's a lot of notes to keep track of, like playing the Rach 3 blindfolded. I love Pandora's product and use it often but still wouldn't touch the investment with a 10-foot conducting baton. Pandora is a rock-bottom one-star CAPS stock (out of 5) for a reason: The risks outweigh the opportunity by a long shot. If we don't get rickrolled this time, it's only a matter of time.

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.