About 44 per cent of respondents said the botched market debut has made them less favourable toward Facebook, according to the survey conducted from May 31 to June 4. The poll included 1,032 Americans, 21 per cent of whom had no Facebook account.

Facebook's 900 million users make it among the most popular online destinations, challenging entrenched Internet players such as Google Inc and Yahoo Inc. But not everyone is convinced that the company has figured out how to translate that popularity into a business that can justify its lofty valuation.

Shares of Facebook closed on Monday's regular trading session down 3 per cent at $26.90. Facebook did not have an immediate comment on the survey.

While the survey did not ask how other forms of advertising affected purchasing behaviour, a February study by research firm eMarketer suggests that Facebook fared worse than email or direct-mail marketing in terms of influencing consumers' purchasing decisions.

"It shows that Facebook has work to do in terms of making its advertising more effective and more relevant to people," eMarketer analyst Debra Williamson said.

Those concerns were exacerbated last month when General Motors Co, the third largest advertiser in the United States, said it would stop paid-advertising on Facebook.

Measuring the effectiveness of advertising can be tricky, particularly for brand marketing in which the goal is to influence future purchases rather than generate immediate sales.

And the success of an ad campaign must be considered in relation to the product, said Steve Hasker, president of Global Media Products and Advertiser Solutions at Nielsen.

"If you are advertising Porsche motor cars and you can get 20 per cent of people to make a purchase, that's an astonishingly high conversion rate," said Hasker.

"If you are selling instant noodles, maybe it's not," he said.

Wanting engagement
About two out of five people polled by Reuters and Ipsos Public Affairs said they used Facebook every day. Nearly half of the Facebook users polled spent about the same amount of time on the social network as six months ago.

The survey provides a look at the trends considered vital to Facebook's future at a time when the company has faced a harsh reception on Wall Street.

Facebook's $16 billion IPO, one the world's largest, made the US company founded by Mark Zuckerberg the first to debut on markets with a capitalisation of more than $100 billion.

Its coming out-party, which culminated years of breakneck growth for the social and business phenomenon, was marred by trading glitches on the Nasdaq exchange. A decision to call certain financial analysts ahead of the IPO and caution them about weakness in its business during the second quarter has triggered several lawsuits against Facebook and its underwriters.

Forty-six per cent of survey respondents said the Facebook IPO had made them less favourable towards investing in the stock market in general.

While Facebook generated $3.7 billion in revenue in 2011, mostly from ads on its website, sales growth is slowing.

Consumers' increasing use of smartphones to access Facebook has been a drag on the company's revenue. It offers only limited advertising on the mobile version of its site, and analysts say the company has yet to figure out the ideal way to make money from mobile users.

Facebook competes for online ads with Google, the world's No 1 Web search engine, which generated roughly $38 billion in revenue in 2011. Google's search ads, which appear alongside the company's search results, are considered among the most effective means of marketing.

The most frequent Facebook users are aged 18 to 34, according to the Reuters/Ipsos survey, with 60 per cent of that group being daily users. Among people aged 55 years and above, 29 per cent said they were daily users.

Of the 34 per cent spending less time on the social network, their chief reason was that the site was "boring," "not relevant" or "not useful," while privacy concerns ranked third.

The survey has a "credibility interval" of plus or minus 3.5 percentage points.