New guidelines have come out telling vloggers that they need to be clear and honest with their followers if they're being paid to say something is good.
It's after Newsround raised a complaint, in November 2014, with the Advertising Standards Authority which makes the rules for adverts in the UK.
Newsround highlighted a group of UK vloggers who were paid to say good things about Oreo biscuits, but none of the videos were labelled as adverts.
Now if a vlogger is being paid to say something good about a particular product or service then they must clearly say that it's an advert.
It's so that everyone knows exactly when they're watching an advert and when they're watching an ordinary vlog.
Guy Parker, from the Advertising Standards Authority said, "It's important that Newsround made that complaint.
"It's just not fair if we are watching a video by a vlogger and we don't know that a brand has paid for the content of that video."