Americans spent more time socializing on Facebook than searching with Google for the first time in August, and Yahoo edged out the search giant in monthly traffic, according to new data from marketing research firm comScore.

Users spent 41.1 billion minutes on Facebook in August, 39.8 billion minutes on Google, and 37.7 billion on Yahoo. Yahoo beat out Google in monthly traffic, with 179 million unique visitors to Google's 178.8 million. Microsoft came in third with 165.3 million.

It's not as devastating as it sounds. As a search engine, Google is a gateway to the Web. As Yahoo pointed out in the ad that slyly bashed, "you come to this place so you can leave." Google strives to direct users somewhere else in milliseconds. Facebook and Yahoo would love for you to linger for hours, reading the news, liking things and generating ad impressions.

You could take this data point as another unfavorable juxtaposition between the massive, institutional corporation and the spunky hacker-centric newcomer. But Facebook and Google have had similarly rapid growth in time spent since 2006 as AOL sites declined dramatically and Microsoft sites declined slightly, suggesting they have more similarities than differences.

And this doesn't mean advertisers will jump ship from Google to Facebook. Some advertisers will more readily buy a search ad, where a user is looking for something specific and scanning the page for what she wants, rather than advertise on Facebook next to a bunch of interesting content that a user is very absorbed in. Or some advertisers may be shilling something with a social bent, and prefer Facebook.

However, Google may be feeling some heat with these new numbers. ComScore tracks traffic for Google sites, not just, which includes YouTube - and Facebook is now the third largest video site.

Right now, users can increase the amount of time they spend on Google and Facebook; they just have to start spending more total time online. But at some point, total time spent on the Internet will max out (we hope, although in theory you could be on mobile and wireline connections all day and then hook yourself up to the Internet of Things at night to track your snoring). When that happens, minutes spent where will become a zero sum game - if Facebook gains share of users' time, it will mean time not spent on other sites. That's when the competition will really get fierce.

What do you think? Should Google feel threatened by Facebook or Yahoo?