Blu-ray sales double over last year. But don't celebrate yet.

Blu-ray's first report card of 2009 has arrived. The high-definition discs started off the year with a great sign of growth.

Americans bought about 9 million Blu-ray titles from January through March. That's nearly double the 4.8 million that sold during the first quarter of 2008, according to Adams Media Research.

The figure is a strong bullet point against detractors who think Blu-ray is just an interim format, a bump on the road to digital distribution. Despite the dragging economy, consumers are willing to hand over $20 or $30 per HD movie, and many times more than that for the 10.5 million Blu-ray players, the Adams report says.

But the "doubling" statistic is not quite as impressive as it sounds.

Bill Hunt at The Digital Bits points out that Blu-ray's sales trajectory is behind that of DVDs. He blames this on the recession. (Blu-ray adoption is actually ahead of what it was for VHS when that format was rolled out back in the late '70s.)

Second, the time frame doesn't give an accurate picture of Blu-ray's progress. January and February of last year were the final days of the format war against HD-DVD. Before March 2008, many consumers hesitated to pick either side, waiting to see which coalition of companies could knock out the other. Of course Blu-ray is doing better this winter compared to last year, when HD-DVD was hogging half of the spotlight. The real indicator will be the second quarter of 2009.

While we wait, Microsoft, one of the early HD-DVD backers, released an odd sign of support for Blu-ray. The 60-second spot has a mom and son running around Best Buy, hunting for the perfect laptop. By far the most passionate line in the video comes when they hover over a Sony Vaio and exclaim "Blu-ray!"

HD movies kinda go to waste on a 16.4-inch screen, but the happy pair walk away with the Vaio nonetheless.

[Video Business via CNET]