On the same day that AdAge ran a skeptical piece “Can Nielsen Still Reign Supreme?,” Nielsen Co. announced plans to acquire a fast-rising rival company in IAG Research, to the tune of $255 million.

The move gives Nielsen a critical new metric to offer to clients — one that measures not just how many people are watching a given ad, but what they actually think of it. IAG Research uses surveys from 200,000 regular participants that offer clients information on which ads and shows viewers are actively engaging with, positively or negatively. Nielsen was no doubt worried by the trend of top advertisers demanding that IAG be included on ad buys. From Ad Age:

In 2006, NBC signed a deal with Toyota that required the network to use data from IAG Research to demonstrate its viewers paid attention and could recall particular details about a TV show.

Nielsen can use the additional credibility in its ratings company, still stinging from revelations that they may have overstated the audience for some major and minor cable channels (including E! Entertainment and Oxygen) by 20 percent. The company has been on a bit of an acquisition binge as of late, as noted by Agency Spy:

Although Nielsen is looking pretty nimble these days (the company has snapped up Telephia, Audience Analytics and BuzzMetrics, too) they can’t buy the whole lot of ‘em including Rentrak, TNS and the pugilistic Group M’s Irwin Gottlieb and his mafia.