Procter & Gamble, the largest ad spender in the world, is cutting down on its targeted Facebook ads, according to The Wall Street Journal.

The reason: The company decided the ads weren't effective.

Facebook stock fell immediately following the news but is trading at about even for the day.

"We targeted too much and we went too narrow," Marc Pritchard, P&G's chief marketing officer, told The Journal. "And now we're looking at: What is the best way to get the most reach but also the right precision?"

One example cited by The Journal explains P&G's position well. Two years ago the company tried targeting Facebook ads for its Febreze air freshener at "pet owners and households with large families." Sales for Febreze "stagnated" during the campaign but went up when P&G opened it up to everyone over 18 years old.