In the ongoing search wars, Yahoo has encroached on Google territory, occupying the search space in iVillage. The women's web publisher said it would replace Google search on its pages beginning September 1 and will begin using Yahoo as its search engine, including advertising listings, reports AdWeek. Moreover, Yahoo's Content Match contextual text advertising will replace Google's AdSense advertising adjacent to iVillage articles.

Google is facing more competition in the contextual advertising market, which it dominates, as some online publishers have defected to the likes of Quigo, IndustryBrains and ContextWeb. And Yahoo is launching its own self-service contextual listings program for small sites that now use Google's AdSense.

Google and iVillage had been partners for two years.