Half of Americans think Facebook is a passing fad, according to the results of a new Associated Press-CNBC poll. 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 was too high.

The company Mark Zuckerberg created as a Harvard student eight years ago had its IPO Friday.

That’s testament to the impressive numbers Facebook has posted in its relatively brief history. 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. In all, some 900 million people around the world use it. Facebook’s revenue grew from $777 million in 2009 to $3.7 billion last year. And in the first quarter of 2012 it was more than $1 billion.

Young adults, a majority of whom log on to Facebook daily, are more willing to dance to their hoodie-wearing piper, 28-year-old CEO Mark Zuckerberg. Among Zuckerberg’s peers, adults under age 35, 59 percent say Facebook is a good bet. Compare that to the views of senior citizens: Only 39 percent age 65 and over say Facebook shares are a good investment. Nearly half of Gen X’ers (ages 35-44) say the company is a good bet, as do 55 percent of middle-aged people.

Young people aren’t just connected. A third log on several times a day. Despite the intensity of their use, a narrow majority of young adults predict Facebook’s appeal will fade (51 percent), fewer think it will stick around as a service (44 percent).

The public overall is similarly divided on the company’s future. Just under half of adults (46 percent) predict a short timeline for Facebook, while 43 percent see staying power.

Phone customer satisfaction evens out

NEW YORK — Improvements in customer satisfaction at Sprint Nextel and AT&T have narrowed differences among the Big 4 wireless carriers to the point that they’re basically even in terms of pleasing their subscribers, according to a study released this week.

The American Customer Satisfaction Index puts Sprint, AT&T, T-Mobile USA and Verizon Wireless within two points of each other on a 100-point scale of satisfaction.

That’s the smallest spread since the survey started in 2005. It’s also within the margin of error at plus or minus three points.

Last year, AT&T clearly trailed the pack, while Sprint and Verizon led. That was a surprising development for Sprint, which was last as recently as four years ago. Sprint CEO Dan Hesse has emphasized customer service.

AT&T recovered this year, with a three-point increase to 69. It shares that score with T-Mobile USA, the No. 4 carrier by size. Verizon and Sprint are at 70 and 71, respectively.