Nielsen IAG measures viewer response to all primetime Spanish-language ads and programs on the leading Spanish TV networks. This syndicated data service was established in August 2007 to complement Nielsen IAG's English-language service, which has been measuring program engagement and ad performance on the broadcast networks since 2001 and major cable networks since 2003 through its panel of 2 million-plus viewers. For all commercials in both English and Spanish, Nielsen IAG tracks ad break-through, brand recall, message communication, and likeability.

The Spanish-language service allows advertisers to optimize their creative rotations in-flight, monitor ad wear-out, track performance relative to key competitors, identify programs which deliver more engaged viewers, and compare performance of their Spanish to English spots in order to allocate ad dollars most effectively.