A new Associated Press-CNBC poll shows half of Americans think Facebook is a passing fad. And, in the run-up to the social network's initial public offering of stock, half of Americans also say the social network's expected asking price is too high.

More than 40 percent of American adults log in to the site —to share news, personal observations, photos and more— at least once a week.

The company Mark Zuckerberg created as a Harvard student eight years ago is preparing for what looks to be the biggest Internet IPO ever.

Just a third of those surveyed think the company's expected value is appropriate, 50 percent say it is too high.

Half the people surveyed say they think Facebook is a good bet, while 31 percent do not.

(Copyright 2012 by The Associated Press. All Rights Reserved.)