Old, TV-style ad measurement metrics are becoming vogue in the data-driven world of online advertising. But AOL Networks CEO Bob Lord says ads measured for audience reach don’t work as well alternatives.

“As we move in to the ability to buy at an impression level …  you start to really question the GRP (gross rating point) measurement system,” Lord tells Beet.TV.

“What advertisers are looking for is a conversion – they want to sell a hotel room, get a dealer appointment to buy a car or complete a credit card application. Right now, reach doesn’t necessarily mean that I’m going to get great results.”

As ad group Mindshare recently wrote: “GRPs have been used successfully for TV planning and measuring since the 50. However, GRPs are a currency which aid planners and are not a true reflection of reach.”

Lord says: “If I’m able to refine the book of impressions that I offer to an advertiser that I know are going to convert, they’re going to be a smaller set but they’re going to be much more effective.”

We spoke with Lord in Manhattan at the Adap.tv Worldwide Publisher Conference.