Influencers in France could face two years in jail, or fines of up to €300,000, if they are found to have broken new regulations.
The legislation was formally passed by the French Parliament last Thursday.
The new laws aim to protect consumers from misleading or fake commercial practices online, and enshrine the status of influencers as legal entities.
Some 15 agents from France's Direction Générale de la Concurrence, a body which regulates commerce and competition, will take responsibility.
Lara Marlowe, Paris-based author and contributor to The Irish Times, told The Pat Kenny Show there are a lot of influencers in France.
"The Ministry of the Economy says there are about 150,000 of them," she said.
"It's a huge industry, it's really a whole parallel economy.
"51% French people have said they would rather buy something that is recommended by a person who talks sincerely about a brand that he or she uses, than pay attention to traditional advertising.
"A very high percentage of French people, especially young people, do their shopping on the internet.
"44% of Generation Z, people born since 1996, say they bought things after they heard them advertised on Instagram".
Ms Marlowe said this new law came about after spat between a YouTuber with six million followers, known as 'Booba', and an influencer named Magali Berdah.
"They both filed lawsuits against each other, she's suing Twitter, and he's got a hashtag 'influvoleurs' - which means influ-thieves, if you like," she said.
"He's done a rap song called 'Certified Liars' - so there's been a lot of talk since the beginning of this year about influencers.
"The Minister of the Ecomony actually approved of Booba, and said 'He's right, there are excesses' and so on".
The French Finance Ministry drew up the world-first law, which was passed on June 1st.
Ms Marlowe said she believes the biggest challenge will be enforcement.
"It requires influencers to have contracts, if you're outside Europe... you in theory have to have a representative in the EU," she said.
"It forces you to have an insurance policy, in case your followers are somehow ripped off by the products that you're recommending, and you're supposed to compensate them.
"Within the past week, three influencers have received warnings from the French government about the content on their social media sites".
Ms Marlowe said the law also restricts the promotion of certain items.
"There was a big market going on in nicotine patches that were being bought by teenagers - that's banned, for example.
"You're only allowed now to promote lotteries and gambling games if children do not have access to those social media - I don't know how you can keep children off of social media.
"So there's this feeling that the consumers are being harmed by the content of these influencers," she added.
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