Launched in February 2004, Facebook is a social networking service founded by Mark Zuckerberg with his college roommates and fellow students Eduardo Saverin, Andrew McCollum, Dustin Moskovitz and Chris Hughes. Early investors include Microsoft and Hong Kong tycoon Li Ka- shing, through his namesake charitable foundation. Facebook’s US$16 billion initial public offering in May 2012 generated huge investor interest although the shares subsequently slumped in price.
How firms buy fake 'likes' for Facebook at 'click farms'
Low-paid workers at 'click farms' create an appearance of online popularity
How much do you like courgettes? According to one Facebook page devoted to the vegetable, hundreds of people find them delightful enough to click the "like" button - even with dozens of other pages about courgettes to choose from.
There's just one problem: the liking was fake, done by a team of low-paid workers in Dhaka, Bangladesh, whose boss demanded just US$15 per thousand "likes" at his "click farm". Workers punching the keys might be on a three-shift system, and be paid as little as US$120 a year.
The ease with which a humble vegetable could win approval calls into question the basis on which many modern companies measure success online - through Facebook likes, YouTube video views and Twitter followers.
British Channel 4 television's Dispatches programme will today reveal the extent to which click farms risk eroding user confidence in what had looked like an objective measure of social online approval. The disclosures could hurt Facebook as it tries to persuade firms away from advertising on Google and to use its own targeted advertising, and to chase likes as a measure of approval.
That particular Facebook page on courgettes was set up by Dispatches to demonstrate how click farms can give web properties spurious popularity.
"There's a real desire amongst many companies to boost their profile on social media, and find other customers as well as a result," said Graham Cluley, an independent security consultant.
The importance of likes is considerable when it comes to consumers: 31 per cent will check ratings and reviews, including likes and Twitter followers, before they choose to buy something, research suggests. That means click farms could play a significant role in potentially misleading consumers.
Dispatches found one boss in Bangladesh who boasted of being "king of Facebook" for his ability to create accounts and then use them to create hundreds or thousands of fake likes.
Click farms have become a growing challenge for companies which rely on social media measurements - meant to indicate approval by real users - to estimate the popularity of their products.
For the workers, though, it is miserable work, sitting at screens in dingy rooms facing a blank wall - with windows covered by bars - and sometimes working through the night. For that, they could have to generate 1,000 likes or follow 1,000 people on Twitter to earn a single US dollar.
Sam DeSilva, a lawyer specialising in IT and outsourcing at law firm Manches in Oxford, says of the fake clicks: "Potentially, a number of laws are being breached - the consumer protection and unfair trading regulations. Effectively it's misleading the individual consumers."
Faked internet use has been a bugbear of the burgeoning advertising industry ever since the web went commercial in the mid-1990s and the first banner ad was rolled out in 1996.
And it is still a problem. In February, Microsoft and Symantec shut down a "botnet" of up to 1.8 million PCs that were being used to create an average of three million clicks per day.