Don’t expect any ads for President Obama across the top of Prospect.org, the online incarnation of liberal monthly magazine the American Prospect. However warmly editors there may feel about him, it is blocking ads from his campaign as part of a pricing dispute that has pitted many political Web sites — on both the left and right — against their ideological allies.
The standoff is an unintended consequence of a broad shift in political advertising this campaign season. More money is going into online ads than ever before, with estimates topping $100 million. But much of this bounty is being distributed through advertising exchanges, such as AOL’s Advertising.com or Google AdSense, that serve as middlemen, bypassing the direct buys that long have been key sources of revenue for Web publications.
The ad exchanges have given campaigns greater precision in targeting voters — 30-something women in swing states who visit parenting Web sites, for example. But the exchanges also take a cut of every buy, leaving less for politically oriented sites in what once was their most lucrative season. They say the trend threatens to starve a diffuse ecosystem of online publications that nurture political conversation.