The Trouble with Facebook's Nielsen Pact

Its new relationship with Nielsen is a big deal for Facebook, which plans to use the resulting data to fight the perception its display ads aren't effective.

But for agencies and their clients, the importance of the resulting research is unclear. Kelly Twohig, SVP, strategy director at Starcom Worldwide, noted this yesterday between sessions at Advertising Week.

"They clearly don't feel they're getting their fair share of upper funnel spending," she told me. "The hard part from a media planning standpoint is that it's such a small part of the buy."

Her point is well made. The attitudinal survey data -- which will include ad recall and purchase intent information -- cannot account for ad impressions that occur off Facebook. And there's a necessary distortion in that consumers may not always be able to distinguish their memory of Facebook's ads from similar ad creative they saw on other sites.

John Burbank, CEO of Nielsen Online, acknowledged the issue but brushed it aside: "Nothing's pure and nothing's perfect," he said. "We're confident enough of the scale that we feel that's not an issue."