Overwhelming majority of big US brands are on Facebook

Brands like Coca-Cola and Expedia are using Facebook to reach consumers through untraditional means, by creating fan pages or applications for users to interact with, without overwhelming them with splashy banner and display ads.

Facebook has over 250m users worldwide and pulls in 340m unique visits every month -- recently leapfrogging Wikipedia to become the fourth most visited website in the world.

The company doesn't charge advertisers to create fan pages on its website, something 83 of the top 100 advertisers in the US have taken advantage of.

Major brands, like Starbucks -- which has more than 3.7m fans on Facebook -- have created discreet product allegiances with consumers through social networking, without having it feel like actual advertising.

Last month, Starbucks gave away nearly 300,000 free pints of its new line of ice cream to Facebook users who signed up for a free coupon.

Sheryl Sandberg, Facebook's chief operating officer, told the Financial Times: "If you look at people's profile pages, you'll see a lot of commercial activity even without advertising."

The website also offers brands a number of targeting tools to ensure their messages are heard by the right audience.

"Facebook's Connection Targeting allows advertisers to target their ads only at users who are fans of their pages, members of their groups or users of their applications.

However, the power of Facebook has resulted in brand damage when it has been harnessed by employees rather than marketers.

There are several examples of brands, including Tesco, Waitrose, Primark and Virgin, who have found themselves in hot water after the stream of communication became a little too open.

In July, Primark was forced to apologise to customers after several employees posted malicious comments on Facebook, calling customers fat, pikeys, and twats.