An advertorial is a paid ad that is laid out to look like an article. It is not mean to look like the regular editorial of the publication or website in which the advertorial is appearing.
Even if the content of the page reads like an article, it’s an ad that belongs to the advertiser, not the publisher. When it appears in a reputable publication or on a credible website, it is created exclusively by the advertiser with no help or input from the publication or website where it appears.
All reputable publications and websites require advertisers who run advertorials to make sure the advertiser’s “article” doesn’t look like the publication’s or site’s articles. Publishers do this by requiring advertisers to use different fonts, numbers of columns and other graphic design techniques to differentiate their ad appearance from the publication’s or website’s editorial appearance.
Reputable publications also require the ad to contain an obvious disclaimer at the top of the page such as “Advertisement,” “Paid Advertising” or “Advertorial.”