Kraft and Pfizer are joining P&G, Unilever and SC Johnson to support Project Apollo, a joint venture between Arbitron and VNU's ACNielsen unit to create a single-source system that measures media exposure and product sales, MediaPost reports (via MediaBuyerPlanner). Neither Kraft nor Pfizer have officially announced their participation, but their names were on an invitation sent to media companies for a meeting about Apollo in New York next week.

The project has already installed more than 5,000 households with product scanning technology from ACNielsen and equipped more than 10,000 individuals in those homes with portable people meters from Arbitron. The PPMs will track media exposure of those individuals as they travel throughout their day and purchased products arescanned by ACNielsen's Homescan system. With information from those two systems, project developers will be able to prove cause and effect of marketing, they believe.

But VNU is in play, with a group of private equity firms having offered $9 billion to acquire it. If that happens, Nielsen Media Research might be broken off and sold, which casts some doubts on the future of the Apollo project, according to the article.

Another mixed signal in the Apollo affair is that Nielsen passed on launching a joint media ratings venture with Arbitron based on the latter's PPM technology. Nielsen said at the time that the decision would not affect the Apollo project, but executives familiar with the situation have said Nielsen is being careful to differentiate its own ratings "currency" from a marketing research tool which, if deployed successfully, could cause marketers to question the long-term need for media ratings.