Microsoft has filed for a patent for technology to target ads to consumers based on their emotional states, taking the notion of "tracking" to a literal level.

In an application filed in December 2010 but just made public last week, Microsoft sought to patent an advertising engine that gauges people's emotional states based on their search queries, emails, instant messages and use of online games, as well as facial expressions, speech patterns and body movements. The ad engine is device-agnostic; as Microsoft noted in its application, "client devices" could include personal digital assistants, smart phones, laptops, PCs and gaming devices.

The patent seems to cover many bases, but the Microsoft product that appears ready-made to deliver emotionally targeted ads is Kinect, the motion-sensing input device that was released for Xbox but now also has a version for Windows. The application states that a user who screams or paces back and forth, when observed by Kinect, could be assigned a negative emotional state by a currently hypothetical advertising engine.

The application further asserts that the advertising engine could have "monetization value" to marketers, since it could ensure that ads aren't wasted on people who are temperamentally unsuited to them.

According to the document:

Weight-loss product advertisers may not want their advertisement to appear to users that are very happy. Because, a person that is really happy is less likely to purchase a self-investment product that leverages on his or her shortcomings. But a really happy person may purchase electronic products or vacation packages. No club or party advertisers want to appear when the user is sad or crying. When the user is emotionally sad, advertisements about club parties would not be appropriate and may seem annoying or negative to the user. Online help or technical support advertisers want their advertisements to appear when the user is demonstrating a confused or frustrated emotional state."

Microsoft didn't respond to a request for comment about its roadmap to build ad products that can be targeted based on a user's mood.

Microsoft's patent application is significant since it speaks to the intent of a giant, data-rich company to take ad targeting well beyond intent-based on search queries or interests expressed through social media. But there are also more nascent players building facial-recognition software for advertisers. Take Affectiva, which measures a consumer's emotional response to ads and has its technology installed in IPG Media Lab's New York showroom, rigged to show how retailers can use it in-store to see how their customers are responding to messaging. An IPG Mediabrands spokeswoman noted that while that data could easily be fed into an engine to determine the best content to display based on a person's reaction, it's not currently built into Affectiva's software.