One of the stranger questions of our modern era: when does being "Internet famous" translate into being, well, actually famous? According to a UK regulator, the magic number is 30,000 followers.

The UK's Advertising Standards Authority (ASA) issued a ruling Wednesday in a case featuring drugmaker Sanofi. A British lifestyle blogger with 32,000 Instagram followers shared a sponsored post in February featuring an image of, and talking about, one of Sanofi's products, an antihistamine and sleep aid called Phenergan Night Time tablets.

The ASA said the Instagram ad constituted celebrity endorsement of a medication, which is not allowed under UK law. Sanofi responded that the 32,000 followers that particular lifestyle blogger had at the time was significantly fewer than major celebrities such as comedian Stephen Fry (359,000 followers) or soccer star David Beckham (55 million followers), and therefore the ad should not be subject to the rules.

In its ruling, the ASA said it "noted Sanofi's argument regarding the comparatively low number of followers" the account in question had as compared to someone like David Beckham but determined that 30,000 followers "indicated that she had the attention of a significant number of people" and that she qualified as a celebrity for the purposes of advertising law.

Celebrity endorsements and other advertising are generally regulated in developed economies, but exactly how much influence it takes to be an "influencer" under the law is something regulators continue to grapple with.

In the US, the Federal Trade Commission made its first-ever complaint against individual social media influencers in 2017 when it reached a settlement with two YouTubers over allegations of deceptive advertising.

Since then, the agency has continued to go after social media advertisers who don't disclose their connections to the products they are shilling. But US law focuses on relationships, not audience size.

According to current FTC guidance, best practice is for basically anyone with a blog, video, or social media presence to make a public disclosure any time they talk about any product, service, or business with which they have any kind of relationship—even if your only subscribers are your mom and your dog.