New York - The number of Americans who listen to online radio at least once a week grew to 42 million, up from 33 million in 2008, according to a new study from Arbitron and Edison Research. Nearly half of the U. S. population, or 49%, 125 million people, have at least once listened to online radio.

Los Angeles - Personalized radio service Pandora has begun incorporating audio ads into the Web-based version of its free streaming music feeds, TechCrunch reported. "So you know, we did not take on audio ads lightly. We try to be extremely respectful of your listening experience, & promise to be prudent," reads a post from the company's Twitter feed. It's unclear whether the company plans to expand the audio ads to its popular iPhone application, which began displaying image-based ads in September.

San Francisco - Social music discovery service Pandora has laid off 20 employees, or 14% of its staff, company founder Tim Westergren announced in a blog post this week.

Washington - The U.S. House of Representatives unanimously passed the Webcaster Settlement Act on Saturday, which would allow webcasters and copyright holders to continue to negotiate royalty payments for streaming music online after Congress suspends its routine business after this week for the elections. A Senate vote on the measure is expected today or yet this week.

San Francisco - Personalized streaming radio service Pandora has announced that Best Buy and Beck's have signed on as the first sponsors of its popular music application for Apple's iPhone and iPod touch, which has been downloaded over 1.1 million times. Best Buy will be the exclusive advertiser on Pandora for iPhone for the first 30 days, while Beck's bought the subsequent 30 days.

Oakland, Calif. - Streaming Web radio service Pandora, which claims about 1 million daily users, says that the recent doubling of royalty payments it must pay to copyright holders may soon force the company to turn off its streams, co-founder Tim Westergren told the Washington Post. "We're approaching a pull-the-plug kind of decision," said Westergren.

Oakland, Calif. - Pandora, a provider of personalized streaming radio, on Wednesday introduced a beta release of its new downloadable desktop application, which allows users to access its ad-supported service directly from their desktops. The application was built on Adobe's AIR platform, and will utilize graphic rather than audio ads.