WPP ad group GroupM made waves earlier this year when it announced it would no longer buy online ads from open exchange marketplaces, as first reported by Beet.TV.

But rival Publicis’ VivaKi digital unit doesn’t think that’s necessarily the right strategy.

“If you limit yourself by saying you’re doing one thing or to the other, I don’t think you’re really delivering best value for the advertiser,” president of the VivaKi’s Audience On Demand sub-group for EMEA and North America, Marco Bertozzi, tells Beet.TV in this video.

“We don’t see that buying in the open exchanges is a problem. It’s where you buy within that that’s an important question mark. Questions of fraud and poor traffic you only get if you are buying in that very long tail. Don’t buy in those at all.”

“Our view is you follow the audience – the audience could be in open exchanges (or) could be in the private marketplaces.”

We spoke with Bertozzi  for “The Road to DMEXCO,” a series of interviews with industry leaders produced in New York, London and San Francisco.    It is sponsored by the automatic content recognition (ACR) technology provider Civolution.

Please find more videos from the series here.  Beet.TV is a media sponsor of DMEXCO and will be covering the conference extensively.