When it comes to behavioral targeting, the prevailing ethos among marketers and ad agencies is “what consumers don’t know, won’t bother them.” As a long NYT piece on the subject shows, there is a lot more targeting going on than consumers might suspect. The paper commissioned a study from audience measurement firm comScore (NSDQ: SCOR), with the intent of providing a snapshot of just how much data on consumers’ online activity is collected in an average month.

From an ad agency standpoint, the gargantuan amount of data collected will mean that media companies will be increasingly dependent on Microsoft (NSDQ: MSFT), Yahoo (NSDQ: YHOO) and Google (NSDQ: GOOG), which have the systems in place to best analyze and organize the user information they collect. Here’s a rundown of some of the findings from the commissioned report:

-- Yahoo, Google, Microsoft, AOL (NYSE: TWX) and MySpace recorded at least 336 billion “data transmission events” - namely, instances of any user activity on their sites - in a single month. That number doesn’t include what their related ad networks recorded. The information being compiled might include a person’s ZIP code, what they searched for, or what they bought. Advertisers will pay more for certain types of data - for example, search tend to command higher prices than other bits of user data.

-- Out of those five companies, Yahoo collected the most data on consumers in a given month - about 110 billion collections, or 811 for the average user. In addition, Yahoo has about 1,700 other avenues of collecting such data, including partner sites like eBay (NSDQ: EBAY), where it sells the ads. The study —which is further explained in detail by the NYT here - does not measure the amount of data captured by the ad networks run by AOL, Yahoo, Google and Microsoft, but, because of the expanded reach ad networks provide, these comScore numbers represent the tip of the iceberg. Just to get an idea, Atlas, which is a unit of Microsoft’s aQuantive, serves 6 billion ads every day.

-- Traditional media sites lagging: While Yahoo’s internet rivals were not far behind in terms of the amount of user data they collected, traditional media outlets appear to be lagging. Condé Nast magazine’s sites, collected just 34 transmissions from each average visitor each month, while the NYTCo’s (NYSE: NYT) sites had 45 transmission events for each user; meanwhile Disney (NYSE: DIS) recorded 64 events and McClatchy (NYSE: MNI) had 49 recorded transmissions for each user. Disney hopes to close the gap by grouping data from sites like ESPN and ABC more closely; meanwhile News Corp (NYSE: NWS). hopes to mine MySpace users activity to figure out how to reach them when they’re on the company’s other sites as well.

-- Making ad targeting more friendly: In spite of Facebook’s Beacon debacle last fall and privacy groups’ growing calls for regulation of consumer data collection, consumers are largely unaware of how detailed the data is on them. But with 85 percent of adults telling researchers like the Samuelson Law, Technology & Public Policy Clinic at the University of California at Berkeley last year that they don’t want advertisers to track them, companies are trying to ensure that such overwhelming displeasure does not turn into greater calls for regulatory action. A separate NYT item details AOL’s latest effort to demonstrate its commitment to policing its behavioral ad targeting. As part of a new ad campaign to cast its ad targeting efforts as benignly as possible, a cartoon penguin helps explain what the process is all about.

• Online Ad Industry Groups Take Steps To Self-Police
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