• by Gavin O'Malley , Staff Writer @mp_gavin, September 14, 2011

Collusion, anyone? In an effort to outsmart Google and top ad networks, AOL, Yahoo and Microsoft have reportedly agreed to share remnant ad inventory with each other. Major Web publishers and ad buyers were briefed on the plan Tuesday night, All Things D reports.

"AOL, Yahoo and Microsoft hope to convince big Web properties to share some of their ad inventory as well, and to get big ad holding companies to funnel some of their purchases through the consortium," All Things D writes. "The strategy is also designed to help them claw back some ad spending that has ended up in the hands of ad networks in recent years."

"This is probably a smart business move, but it's going to make life a lot more complicated for AOL, Yahoo, and Microsoft salespeople who may suddenly find inventory they planned or hoped to sell pulled out from under them," Business Insider writes.

Notes TechFlash: "The plan offers some more insights on how the relationship between Yahoo and Microsoft has developed beyond an online search and advertising deal that allowed Microsoft's underlying Bing search technology to be used on both sites."

"The idea, according to people who attended the meeting: Microsoft, Yahoo and AOL have agreed to sell each other's ‘Class 2 display' inventory -- graphic ads the companies can't sell on their own and would normally hand over to ad networks," All Things D adds.

"In other words, the crap ads," Marketing Pilgrim points out. "The ads that perform so badly or are so overpriced that neither Microsoft, Yahoo, or AOL can sell them directly -- not even with their own skilled sales force." "The ad pact will start at the end of 2011 and will not require exclusivity so each company is free to work with any ad network, even Google," The Next Web notes. "By banding together ... the three companies will share ad revenues in hopes of increasing their total earnings in Google's shadow."