In Lidl SNC v Vierzon Distribution SA before the European Court of Justice, Lidl argued that Vierzon’s advertisement comparing prices was misleading. Vierzon compared the total price for a list of products bought at two supermarkets without showing the qualitative differences between the products on the till receipts.

The question at stake was if Article 3a(1)(a) to (c) of Directive 84/450 on comparative and misleading advertising is to be interpreted as meaning that it precludes any advertising practice which compares, from a price angle, a basket of food products marketed by two competing retail store chains without mentioning the differences between the (food) products.

According to the European Court of Justice an advertisement making comparisons has to show sufficient information of the features that significantly affect the consumer’s choice. In other words, the advertisement has to show the necessary information for a consumer to make an assessment of the advantages of the difference in price and the (possible) differing quality and/or quantity. In order to assess this, the consumer needs more information than just generic names on a till receipt, which was the only information Vierzon’s advertisement showed.

Thus, before running an advertisement making comparisons, (retail) store chains will need to survey what the significant features of each product are according to the average consumer. That may very well include the fact that it concerns A-brand products, or it may not.

It will be up to the lower courts to develop a standard that can be applied to determine which features are capable of significantly affecting the consumer’s choice and thereby creating legal certainty for companies involved in comparative advertising.