Facebook has more than 1.23 billion active users worldwide, with over 50 per cent of all users logging on to it on any given day.
Most of Facebook's revenue comes from advertising and the company is looking at ways to make the site a more effective advertising platform for marketers. This includes selling ads that are more targeted to their users.
However, researchers have found that users of social media websites are less likely to use them to say positive things about their favourite products and services.
Instead, they are more likely to express their opinions about products in intimate face-to-face social situations. This is because most users usually have a wide range of ''friends'' or ''followers'' on social media sites, outside of their immediate family and friends, which deters them from expressing their opinions as they feel more vulnerable to adverse comments.
The research was carried out by Imperial College Business School, Cornell University, Leeds University Business School, Marshall School of Business at the University of Southern California and the Department of Management and Marketing at the University of Melbourne.
Dr Andreas Eisingerich, co-author of the report from Imperial College Business School, said: ''Social media websites such as Facebook have completely revolutionised the way we share information and communicate with each other. However, our report shows that when it comes to sharing recommendations on products and services on these sites, users tend to stay quiet.
They would rather communicate via word of mouth because many users don't want to embarrass themselves online as work colleagues or acquaintances may not endorse or appreciate the same products that they do. Our report could influence how businesses spend advertising budgets on social media websites.''
In the study, the researchers surveyed 407 participants in labs and face-to-face surveys to find out how they communicated about their favourite brands. They found that users are reluctant to endorse products on social media sites due to the perceived risk that they could embarrass themselves if their views are not endorsed or shared by others.
In contrast, sharing information in face-to-face situations among a smaller group of people, usually family and friends, doesn't have the same social pressures, say the team.
The researchers say their findings are surprising, given the fact that social media platforms have made it easier for users to share information at a time and place that is most convenient for them, such as the comfort of their own homes. This should in theory make people more at ease about sharing their experiences and opinions, say the team.
The researchers also found that those who did share their opinions about their favourite products and services did so because it made them feel good about themselves and that it raised their self-esteem. They found that as the user's need for enhancing their self-esteem increases so does their willingness to share their views; Facebook is an effective way for these types of users to seek feedback and validation.
The researchers suggest that the findings of the report can be used by social media companies and marketers to take steps to ensure that consumers do not feel threatened by these online social risks. This includes providing opportunities for consumers to selectively share their opinions with members of their social network.
The report is published in the Journal of Consumer Psychology.