On October 6, 2015, the ECJ issued an important judgment clarifying the application of Article 102 to retroactive loyalty rebates (Post Danmark AS, Case C 23/14). The case, which had been referred to the ECJ by the Danish Commercial Court, The Danish Competition Authority decided in 2009 that Post Danmark had abused its dominant position on the market for mass mailings by applying loyalty-creating and market-distorting rebates for direct mail without demonstrating efficiency gains to the benefit of consumers.

Post Danmark challenged that finding before the national courts, and the Danish Supreme Court made a first reference to the ECJ in Case C-209/10. The Authority had also made submissions in that case concerning a different type of abuse, i.e. low pricing.

The ECJ in its findings stated that in applying Article 102 TFEU, there is no appreciability (de minimis) threshold for the purposes of determining whether there is an abuse of a dominant position. That anticompetitive practice is, by its very nature, liable to give rise to not insignificant restrictions of competition, or even of eliminating competition on the market on which the undertaking concerned operates That said, the ECJ concluded that in order to fall within the scope of Article 102 TFEU, the anticompetitive effect of a rebate scheme operated by a dominant undertaking must be probable.