SIRI), had figured out ways to keep growing its popular service, albeit amid some "fading notes." Last week, the company announced total listening hours for the month of August rose 16% year over year to 1.35 billion hours. The number of people that sign on to the service each month also increased, by almost 30% to 72.1 million, which represents 1% sequential improvement. What this means is that, with a year-over-year improvement of 116 basis points, Pandora now accounts for 7.5% market share of the U.S. radio listening audience. This is impressive growth. Admittedly, I haven't been Pandora's biggest supporter. But there is no way to spin this performance without giving the company its due credit. Unfortunately, however, making money has not been one of Pandora's strengths, despite such solid growth and meaningful market share. Now, with Apple's iTunes Radio, not to mention Google's ( GOOG) All Access service fully in the mix, it just doesn't seem as if Pandora's top-line performance will ever trickle down to profits.