Pandora Pre-IPO Numbers Getting Bigger and Bigger

Here’s some red meat for investors thinking about buying into Pandora’s IPO: Go-go growth numbers for the company’s first three months of 2011.

Pandora says revenue, users, and usage are all way, way up, driven primarily by the streaming music service’s popularity on mobile devices. Losses are up too, but the company has already warned investors that it will be losing money through 2012.

A quick snapshot for Q1, via Pandora’s most recent SEC filing:

Revenue: $51 million, up 131 percent from $21.6 million

Losses: $6.8 million, up 126 percent from $3 million

Registered users: 94 million, up 77 percent from 53 million

Active users: 34 million, up 88 percent from 18 million

Listener hours (total time users spent playing music): 1.6 billion, up 128 percent from 0.7 billion.

In short, pretty much what you want to see if you’re a Pandora bull. Revenue and usage are booming, and expenses are up because the company is spending a bunch of money to keep pace with its growth–it’s doubling headcount for engineers, sales guys, etc.

The key sticking point for Pandora is that as use grows, its music costs grow, too–right now the company is spending about 58 percent of its revenue on royalties. (Which is much less bad than it used to be). So at some point Pandora needs to prove that it can grow ad sales faster than its music costs.

One good sign in that regard is that the company is growing less dependent on Google to sell its ad inventory. This quarter Google accounted for 2.3 percent of Pandora’s revenue, down from 6.3 percent for all of last year, and 11.4 percent the year before that.

And again, it’s worth pointing out that Pandora’s success has been driven in large part by Apple’s iOS and more recently Google’s Android platforms. The company says users access the service via mobile devices 60.3 percent of the time, up from 50.5 percent last year and 23.5 percent the year before.