The NMHH draws attention to dubious internet advertisements

Published: 11 January 2023

We are inundated with ads on websites and social media platforms, around 20 percent of which are so-called hidden ads. According to experts from the National Media and Infocommunications Authority (NMHH), hidden advertising is not necessarily harmful, but it is always worth being cautious about tempting offers.

It is possible to recognise if an advertisement is misleading

One of the main features of dubious advertising is the extreme way of attracting attention. These advertisements are characterised by the use of shocking, disturbing photographs that make the viewer feel uncomfortable, and by the use of tempting promises, in which the emphasis on almost immediate impact is a recurring element. The staff at NMHH has put together a list of things to look out for to spot misleading advertising.

  • Overabundance of logos of scientific-looking organisations in the header of the page.
  • It is also common that a statement made by an “expert”, a “scientist” or the creator of the product is also displayed. It is recommended to make an online search for the name and professional reputation of the person making the statement.
  • One should always be wary of exaggerated claims in advertisements (e.g. 15 kg/30 days without dieting), which are likely to be scams.
  • It is also suspicious if the “customer reviews” displayed on the site are all extremely positive.
  • Contact information should also be checked; if there is only a fillable form there, it is definitely suspicious.
  • When visiting an unfamiliar online shop, the terms and conditions of the site should always be checked.
  • Don’t let the website rush your purchase!



Hidden advertising is advertising where the company/person placing the advertisement cannot be identified, the purpose of the advertisement is unknown, and the link is likely to lead to a dangerous/virus site or try to extort money from the user. Some of these advertisements promote a legal product, but most of them raise concerns.

The research conducted by the NMHH sought to find out how widespread these advertisements are, where they appear, who the advertisers' primary target groups are, who is most vulnerable to misleading advertising and also to provide guidance on how to avoid them.

According to the research, between January and June 2022, around 5.05 million computer users encountered advertisements online, and 95.75 percent of them (4.83 million users) read advertisements that could be classified as hidden. These advertisements reached 3.4 million people per month and nearly 800,000 people per day. During the above 6-month period, the average PC user encountered 5757 advertisements, of which 302 (roughly one in twenty) could be classified as hidden.

From lucky obsidian bracelets to slimming miracle products

Most of the advertisements in the hidden category are some kind of dietary supplement or “miracle cure” promising an immediate improvement in lifestyle and health. In the first six months of the year, the hidden advertisements reaching the most people included a range of weight loss supplements, liver protection products, vision-enhancing “magic sunglasses”, the “enemy of diabetes” and a joint protector product that promises to make you feel 20 again. Since chronic diseases mainly affect older people, these products – together with the respective advertisements – are typically targeted at them. The other reason is the internet habits of older people. These users “surf” more slowly, spend more time on a page, and therefore see the advertisements displayed to them for longer periods of time. In the case of hidden advertisements specifically targeting women, advertisements offering specific diets and weight loss dietary supplements (e.g. “keto diet weight loss challenge”) are ahead of the pack, while among advertisements targeting men,, a site offering NFTs is the most popular (with a reach of 22.9%).

Hidden advertising can be found on social networking sites (e.g. Facebook, YouTube), on search engine interfaces (e.g. Google) and on traditional sites as well.  In terms of advertising, Facebook is clearly the top performer: most internet users load hidden advertisements on this site (3.4 million users) and the highest number of contacts (246 million) are made here. YouTube, being in second place, had 2.6 million users loading hidden advertisements, although the number of contacts was much lower here, at 23.9 million.