The Nielsen Company today released some interesting data about the American Idol phenomenon. I’m pleased to share these key highlights, some of which include references to David Archuleta.

TV ratings

Viewership this season is being propelled by the 35-49 age demographic which comprises 29 percent of the audience. The 50-64 demographic comprises 23 percent of the audience. The 18-49 demographic comprises 50 percent of Idol viewers, the total audience being an average of 27 million this year for each episode. Compare that to 12 million in the first season and 30 million in the fifth season. All in all, Idol, by and far, is today’s most successful show at reaching network television’s most important age demographic.

The power of texting

The average American Idol participant voted via text message 38 times in April 2008, peaking with the April 29 episode. Women submitted 44 percent more text votes than men. Keep in mind that voting by text is only available to AT&T subscribers. Nielsen Mobile tracks text message voting and contest behavior through its panel of 43,000 U.S. wireless lines.

Season 7 contestants and online buzz

Nielsen Online monitors 70 million blogs for buzz volume reported as a percentage. David Cook (14.3 percent), David Archuleta (12.5 percent) and Jason Castro (10.5 percent) have dominated the show’s consumer discussion online. Brooke White continues to be included after being voted off two weeks ago with 7.5 percent buzz volume, while Syesha Mercado, who was eliminated this week, trails with 5.4 percent.

On Hey! Nielsen’s online research panels, Archuleta and Cook have been this season’s most popular contestants, followed by White, Castro, and — surprise — Danny Noriega.

Interesting postscript: Castro’s performances in two instances generated significant spikes in digital download and album sales for original artists. They included Jeff Buckley’s version of Leonard Cohen’s “Hallelujah” which went to the top spot on Hot Digital Songs with 178,000 copies. Later, his take on Israel “Iz” Kamakawiwo’ole’s version of “What A Wonderful World” sent the original track to eleventh on the same chart.

Product placements

Folks, this is part of the reason why the American Idol property is so valuable to Fox. With partial numbers in for the current season, there were nearly 3,300 product placements by the end of March (the first three months), compared to more than 4,300 for all of last season. No surprise which are the most frequently placed brands: Coca-Cola, AT&T, and Ford Autos and Trucks.