Viewability, the recently-defined metric that defines whether an online ad slot is really viewable by consumers is a wholesale change for the industry – but its benefits may be blunted as too many platforms are vying to help advertisers capitalize, according to Ziff Davis CEO and IAB chair Vivek Shah.

“We’re creating a standard in digital media that is different and better than exists in other media – it’s groundbreaking, it’s unprecedented,” Shah tells Beet.TV in this video interview. “We’re changing the currency of a $40 billion industry.”

But Shah is concerned about proliferating platforms that show advertisers the new metrics. “We have way too many viewability vendors,” he says. “There are 15 vendors today accredited by the MRC; there may be another 15 in the queue, from what I understand.

“Publishers can’t be asked to become compatible with 15 to 3o different systems. There are really only two to three ad servers… it’s taken us 18 years to bring discrepancies in to a tolerable range.”