Speaking as part of a panel session called 'Buyer Beware' at Advertising Week here on Wednesday, Montgomery said: "It’s like having unprotected sex if you buy at the (cheap) end of the tail."
He was echoing the sentiments of Randall Rothenberg, the president and chief executive of the US IAB, who said in February that the digital advertising industry needed to stop having unprotected sex.
Both Montgomery and Rothenberg were referring to the risk of online ad fraud, in which ad spots are bought and sold, but never seen by a real person. Cheaper ad spots often leave buyers unaware of who is viewing the ad and where.
David Cohen, EVP chief investment officer and president global partner at Universal McCann, agreed: "There is a reason why something is being sold at a 40c CPM (cost per thousand)."
Cohen rejected the idea that there was more pressure on online ads than in other media, however, and said clients "want prices to go down across the board".