After a spectacular IPO in early June, Pandora Media (NYSE: P) has treated investors to a world-class roller-coaster ride. In less than three months, share prices have bounced between $11 and $20, excluding that insane first trading day -- and all of this before we laid our eyes on the company's first earnings report.

As it turns out, the report wasn't the horror story investors were expecting. The stock jumped as much as 13% in after-hours action and settled on a still-respectable 8% gain in late-Friday trading. That $13.50 level represents an 11% swoon in August … but then the S&P 500 has lost 9% of its value, too. Fellow recent IPO LinkedIn (NYSE: LNKD) lost 28% so far in August and new-media mavens Netflix (Nasdaq: NFLX) and Sirius XM Radio (Nasdaq: SIRI) are down by double-digit amounts as well. All things considered, Pandora is holding up fairly well in this market.

Pandora's numbers look decent. Revenue jumped 117% year over year to $67 million, with 87% of sales coming from advertising and the rest from subscription services. Part of Pandora's allure lies in the low-cost access to millions of music tracks, so I don't expect this equation to move very far in the direction of subscription revenues. I'd love to see the company prove me wrong, however -- Netflix and Sirius would be a fraction of their profitable selves under an ad-supported business model.

Google (Nasdaq: GOOG) can get away with that, but only because its search and ad services are so ubiquitous that we expect them everywhere. I remain unconvinced that Pandora can pull off the same trick.

For now, a better revenue model may not be strictly necessary. Pandora reported a non-GAAP net profit of $0.02 per share, ahead of the Street's breakeven projection, and even generated a modest $0.5 million in operating cash flows.

I find the early numbers intriguing, but am not ready to plunk down real money on this stock yet. Pandora remains firmly seated on my watchlist for now, and it only takes a click to put it on yours as well. If and when Pandora broadens its revenue sources, gets into car stereos in a big way, or utterly fails to do any of the above, informed investors like you and I will be ready to pounce.