Columbia, MD - Dec 21, 2009 - Arbitron plans to accelerate a scheduled increase in its diary market cell-phone-only (CPO) household sample target. Arbitron now plans to raise the proportion of its diary sample coming from CPO households to an average of 15 percent across all of its diary markets in the U.S. by Spring 2010. When implemented, the planned increase in cell-phone-only household sampling will represent an increase of 50 percent from the year-end 2009 sample target, which is equal to an average of 10 percent. Previously, Arbitron had announced that this increase was scheduled for completion by year-end 2010.

Effective with the current Fall 2009 survey, Arbitron implemented CPO sampling in all of its 268 diary markets, completing the rollout of CPO sampling to all Arbitron-rated radio markets in the 50 United States, including diary- and PPM-based ratings services.

Arbitron began CPO sampling in 151 diary markets during the Spring 2009 survey where CPO sampling yielded a 25 percent gain in the Designated Delivery Index (DDI) sample quality metric for Persons aged 18-34. CPO sampling helped maintain the sample quality momentum in Summer 2009 diary markets where DDI improved by 11 points over the Summer 2008 survey for Persons aged 18-34 in markets with CPO sampling.

According to Arbitron, people who live in CPO households are more likely to be age 18-34. While the CPO sample target was an average of 10 percent of the total (12+) diary sample in Spring 2009 across all markets, it represented approximately 28 percent of the 18-34 in-tab sample. "With this new increase in spring 2010, the percent of 18-34 sample represented by CPO households should be closer to 40 percent," said Dr. Robert F. Henrick, executive vice president, customer solutions, Arbitron.