The trick to sustaining the arbitrage is for the ad platform provider to align with new inventory sources that are cheaply priced relative to the ad network's algorithms and client makeup. "You find a place where the publisher can improve the yield and the marketer can improve performance," he told AdExchanger in a follow-up interview.
A larger question is whether margin expansion should be the goal. "It may well be there's only so much revenue to be had at that margin," he said.
When that happens, growth must come from other directions, such as regional expansion, tapping new advertiser segments, and partnerships such as Rocket Fuel's deal with CCI in Japan.
But managing media costs remains a key method for preserving margins. And increasingly, that's done by hiring people to interface directly with the sell side, to build relationships there and attempt to secure exclusive inventory access.
Google's Bonita Stewart, VP of partner business solutions in the Americas, has recently secured a number of big publisher deals. She told AdExchanger last week, "You will see more announcements around how we are working with publishers, how we are connecting the demand and the supply, how we are driving incremental value for publishers and how effectiveness of our technology will deliver to the bottom line."
The absorption of WPP Group's 24/7 Media by its corporate sibling Xaxis can also be seen in this light. The deal was pitched to the marketplace as a way to obtain exclusive inventory access for marketers. But locking down supply also brings the helpful, ancillary benefit of preserving margins.
"You will have to bet that over time, in the pursuit of growth, there won't be that much inventory," Wieser said.
The ad platforms know this, and they're acting on it.