Social media might be losing its allure for corporate brands, according to a Business Network International survey which has found that 75% of companies are beginning to decrease their usage of social networking sites.

However, of the 1,000 companies polled, most are still using Twitter and Facebook to build stakeholder relationships.

One of the major detractors from Twitter's popularity among corporate brand managers is that it is difficult to determine the actual impact virtual advertising has on business. Despite Twitter's promoted tweets, which propel brand messages to the top of the page, the open-forum nature of the site still leaves brands vulnerable to uncontrolled criticism from users.

Another survey, carried out by the research company Pearlfinders, polled 5,000 marketers and found there was a 16% drop in social media marketing worldwide.

Despite the decrease, companies continue to engage with their customers via social media. Greggs bakery recently celebrated reaching 500,000 likes on its Facebook page and plans to implement a Fan Van that will feature the faces of its Facebook fans.

Similarly, Visa, which spent £64 million to sponsor the 2010 and 2012 Olympic Games, has undertaken mass efforts to engage its Facebook fans via 'cheers' for the world's athletes. Sociagility, a website tracking Olympic sponsors' use of social media rates Visa favourably for these efforts but finds Visa lacking in the 'trust' and 'receptiveness' categories.

American broadcaster of the Games, NBC, has incited public outrage due to actions on Twitter - outrage that has been simultaneously expressed through tweets. NBC has limited American viewers' access to watching live Olympic events, prompting Independent reporter Guy Adams to tweet NBC's corporate email address. His account was suspended by Twitter, a sister company of NBC, eliciting criticism of both companies. In the day following Adams' suspension, there were 32,000 mentions of #NBCFail and 14,000 mentions of @guyadams on Twitter.