What does it mean to be a man? asks Lisa Terry in the introduction to a new report on advertising trends. Once upon a time, it was all so clear.

Advertising Age, the magazine that tracks the ins and out of the advertising industry, is trying to help marketers understand the elusive male mind with a 40-page report called Dudes to Dads: U.S. Men's Attitudes Toward Life, Family, Work. The report, launched this week and available online for $249, aims to bring marketers up to speed on the changing tastes of male consumers across various demographics.

The task is a challenging one, according to Terry, who suggests that marketers habitually pay too little attention to men's habits, choosing instead to focus their efforts on targeting women. That's understandable, seeing how women, by some estimates, are responsible for a staggering 83 percent of all purchases made in the United States. But traditional consumer habits are becoming more difficult for marketers to rely on -- particularly in a world where gender roles are changing, populations are becoming more multicultural and a down economy has made consumers of all stripes more careful about where they spend their money.  

Marketers have done a good job of keeping up with women's evolving lives through this tumult, Terry wrote. But despite an explosion in the availability of data and tools to gain insights into all kinds of niche audiences, brands haven't always kept up with how men's lives are changing.

So what insights can man-hunting marketers expect to glean from the new report? For one thing, the familiar stereotype that older men respond to old media while younger men are flocking to the Internet is only partially true. While male Millennials, the demographic  born between 1977 and 1994, are more likely to respond positively to Internet videos, they are also more likely than their older counterparts to pay attention to the print ads they see in shopping malls, medical offices and bars or pubs. Gen-X males, born between 1965 and 1976, respond to both these types of ads to a lesser degree, as do male Baby Boomers, born between 1946 and 1964.

One area of cross-generational agreement, however, is in the utter distaste for ads on mobile devices. Sixty-five percent of men overall call cellphone ads annoying, wrote Ad Age's Ann Marie Kerwin, with Millennials leading the pack. That statistic could spell trouble for many top Internet companies as online habits continue to shift from PC's to mobile devices. Facebook (Nasdaq: FB), in the lead-in to its much-hyped IPO this spring, sheepishly admitted that it has yet to monetize users who log on to the site via smartphones.

The cultural aspect to Ad Age's research seems to imply that marketers should throw away all their old ideas about gender stereotypes (pay attention, Seth MacFarlane).  Outdated messages, such as the 'bumbling dad' or 'efficient housewife,' are not likely to pack the same punch going forward, wrote Kerwin. In fact, seventy-one percent of men say that keeping a neat, organized home is a top priority for them.    

Most of the data in Ad Age's report comes from last fall's Survey of the American Consumer, a widespread study of consumer habits conducted each year by the research group GfK MRI. If the research is correct, marketers hoping to reach dudes and dads might have to think beyond video games and backyard grills. Do they make Roombas with beer holders?