A recent raid on a 'click farm' in Thailand has shed some light on the clandestine online industry.
Three Chinese men arrested in Thailand this week have admitted to operating a 'click farm,' using 476 mobile phones and 347,200 SIM cards to accumulate "likes" and views on WeChat, a Chinese social media app.
Thai immigration authorities say the three men told them, they were paid according to how many likes and views they generated. The men reportedly earned between $3,900 and $5,800 per month.
So what is a 'click farm'?
A 'click farm' is a form of internet fraud that involves paying employees to increase the social media presence of companies and people for popularity and profit.
It often employs workers who are required to click 'like' on Facebook, 'follow' on Twitter and to rack up views on YouTube, or click on online adverts.
Farms typically operate from countries such as Thailand and Bangladesh. The number of employees per farm is unclear because of the clandestine nature of such operations.
David Vaile, the co-convenor of the UNSW Cyberspace Law and Policy Community, says farms are usually situated in developing countries because they likely have "less-developed regulatory systems" to monitor such practice.
But the main reason, he says, is that labour is cheap in those countries.
Employees are known to be paid very low wages, as seen in a case in 2013 where the boss of one 'click farm' in Dhaka was found to be paying his employees $15 for every thousand "likes".
In a 2015 investigation by 'The Times', it was found that companies in India were offered $1 deals for 1000 clicks.
When 'The Times' posed as a potential customer for Indian Facebook Likes, the 'click farm' promised to: "give you 1000 likes on Facebook in six to seven days".
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Why should we care?
When 'click farm' employees are clicking online advertisements, they are helping generate virtual activity into money in the real world.
And when they are clicking Facebook likes and Twitter follows, Mr Vaile says they remove "any basis of trust" in the popularity of a profile page.
However, Mr Vaile says in an age where telecommunications providers, social networks and other companies track people's every online move, 'click farms' may actually work to protect people's privacy.
He says 'click farms' may evolve into a service that protects people from "the omnivorous and insidious totalitarian gaze of surveillance".
Someone's online activity, such as the advertisements they click on, helps to form psychographic profiles on people that advertisers can analyse to determine how to target and influence them to buy their products.
Employees clicking on advertisements in a random fashion help undermine and confuse these surveillance methods, affording online users greater privacy.
How much money is involved?
It is hard to estimate how much the industry is worth, says Mr Vaile, because a lot of 'click farms' are undercover, they're not high on authorities' agenda to track, and they're "changing and mutating quite a lot".
One of the latest available estimates on the industry's worth was made in 2015 by Forensiq, a service that detects fake internet traffic for customers.
It reported that it was worth $785 million and growing at about 20 per cent per year.
But Mr Vaile warns about the potential vested interests behind commercial companies providing such estimates.
Social media companies are aware about the phenomenon and are monitoring it.
Facebook says on its website it now performs frequent purges by manually reviewing clicks it believes are not valid.
Twitter says it also takes action, deleting accounts that employ 'click farms'.
SBS World News has contacted Forensiq for comment.