Social media, which include blogs, social networking sites, have become important avenues for commercial practices, especially hidden ones. They are sometimes used by traders to promote and advertise their products.
For example, several Member States have reported that cosmetic companies have paid bloggers to promote and advertise their products on a blog aimed at teenagers, unbeknownst to other users. In such cases, the authorities considered that the bloggers concerned were engaging in hidden commercial practices.
Unfair commercial practices may also occur on price comparison websites. An obvious case is when an online price comparison service belongs or is linked to a trader and is used to advertise its products. For example, the site "quiestlemoinscher.com" (literally "whoisthecheapest.com"), a grocery price comparison service created by a French major supermarket company, was considered by French courts to be a trader's website and a tool for comparative advertising.
In the case of professional but independent price comparison websites, the trader's activity consists of sourcing prices from retailers and passing this information on to consumer. Such service providers should therefore also be considered as traders and they would therefore be bound by the Directive's provisions. In such cases the criteria and methodology used by the services providers and any contractual links with certain traders would have to be disclosed to the sites' users.
However, where individuals provide price comparison information purely on a non-professional basis, they are not considered as engaging in commercial practices. Again, it is for national enforcers to assess whether such sites fall inside the Directive's scope on a case-by-case basis.
 Tribunal de commerce de Paris - 29 mars 2007 - Carrefour c/Galaec (la coopérative groupement d'achat des centres Leclerc).