Bloggers and social media influencers are being warned they'll be named and shamed if they mislead their followers.
The Advertising Standards Authority (ASAI) is telling the online stars that they need to make it absolutely clear about when content is paid for.
The authority is hosting an "educate and inform" event at Facebook's headquarters in Dublin today.
Over 100 agencies, brands and bloggers will be instructed on when they need to disclose that something is an advert.
ASAI head Orla Twomey said the authority will publish the details of anyone who doesn't admit when their content has been paid for.
“The sanction is against both blogger and advertiser,” she said.
“It is the ‘name and shame’ sanction where we will publish the adjudication of the complaints committee.
“Their reputation – their brand reputation – is very important to them.
“So they need to be careful [in case] their follower thinks they are likely to be misled by them.”
She said consumers need to know when they are being advertised to – with more and more brands and influencers working together to co-create content.