Fake fans cheap to get
It barely burns a hole in one's pocket to buy fake followers on social media, says a social media expert.
"It is extremely inexpensive. You can pay anything between $10 to $20 (on online sites that specifically offer this service) for anything from 1,000 to 10,000 fake followers and see an overnight boost," said Dr Michael Netzley, academic director of executive development at Singapore Management University.
This can create a good and positive impression, and advertisers are not likely to devote time and attention to check these followers.
Dr Netzley calls the Instagram purge a good way to "get the crap out of the system".
For Mr Lars Voedisch, managing director of public relations and social media consultancy PRecious Communications, the move is beneficial in two ways.
"For normal users like us, we want to believe that the people following us are real," he said.
"For networks like Instagram, it is about cutting down attempts at gaming the platform and algorithms as it negatively affects trust in advertising products."
Mr Voedisch also encourages advertisers to do their research and not focus on absolute numbers alone.
"Look at changes over time and look at engagement figures - how many of the followers engage through 'likes' or comments.
"Brands have to do their homework and benchmark against industry averages," he advised.
Dr Netzley also encourages companies to approach a third-party measurement company which does health runs of social media accounts.
Companies like blog advertising firm Nuffnang and social media advertising community ChurpChurp practise vigilance.
While they look at numbers first, they also take into account engagement in terms of likes, and the quality and relevance of comments.
Tracking tools are also used to check the growth of followers on social media accounts.
Ms Yang Hui Wen, regional director of the Netccentric Group, which owns the two companies, told The New Paper: "We have noticed the pattern before but it's usually semi-popular bloggers who want to give the appearance of a large following. It is a shallow world, in that sense."
Ms Ngeo Mei Ting of make-up and skincare company Benefit Cosmetic Singapore said she would take measures to conduct stricter checks from now on.
She said: "We usually hand-pick our influencers and make the effort to meet and get to know them. The relationship is usually built on trust."
Their social media influencers include popular local actress Nurul Aini and YouTube breakout star and host Maimunah Bagharib.
Ms Ngeo said: "Still, I will now be more wary and monitor more closely after this (purging)."