• by David Goetzl  @dgoetzl, August 6, 2010

While Rentrak trumpeted a deal with Charter last week giving it access to set-top-box data in a slew of markets, Nielsen has had a similar arrangement with the cable operator for months -- forming the basis for an STB test it is conducting. The deal gives Nielsen access to STB data from 1 million Charter homes in 35 markets, which include Dallas and Boston.

But while Nielsen is analyzing that full bucket of data, the test program to determine optimal use of STB data only taps into 64,000 homes in three markets.

In St. Louis, Nielsen is gauging performance based on 46,000 homes served by Charter. In Greenville, S.C., the number is 12,000 homes, and it is 6,000 in Reno, Nev.

The footprint in each market is much larger than the traditional panels Nielsen uses, which range from 500 to 650 homes.

Still, the STB homes represent a minuscule portion of all TV households in the respective DMAs. The 46,000 in St. Louis account for about .04%, and the percentages are less in Greenville and Reno.

Competing measurement company Rentrak may be using data from some of the same homes. The ABC affiliate in St. Louis subscribes to its local-market service.

Results from Nielsen's STB test are expected this fall. While homes served by a satellite or telco TV provider are not being used, a Nielsen spokesman said the Charter homes should provide a sound enough base for analysis.

"We are confident that the test sizes are robust enough to provide the insight we need," the representative said.

Nielsen selected the three markets because they represent a cross-section of its local-market measurement techniques. Local people meters are used in St. Louis, and set meters in Greenville, while Reno is a diary market.

With STB data, Nielsen is looking to launch what it calls a "hybrid" product, which would combine results from its traditional panel with the STB-derived information. Hoping to differentiate its offering, it aims to attach demographic data to STB viewing; provide insight for a full market rather than just STB homes; and track whether a box remains on even if a person is no longer watching.

Charter Communications, the country's fourth-largest cable operator, began offering STB data from a pool of more than 250,000 homes in Los Angeles several years ago. But that had obvious limits in reach -- and given Southern California demographics, is not necessarily representative of the country at large.

Rentrak is melding the newly announced nationwide Charter data into its system, which also uses data from Dish Network and AT&T. Rentrak says it offers local-market STB-derived ratings in all 210 DMAs, while it also had service capturing second-by-second viewing for national networks.

Nielsen is aiming just to launch an STB-based product at the local level. The spokesman said there are no immediate plans to join Rentrak in purchasing data from other providers.

"We're in constant conversations with all the MSOs and satellite companies and telcos, but I can't predict whether we'll have a deeper relationship with them," he said.