Case C-23/14: Judgment of the Court (Second Chamber) of 6 October 2015 (request for a preliminary ruling from the Sø- og Handelsretten — Denmark) — Post Danmark A/S v Konkurrencerådet (Reference for a preliminary ruling — Article 82 EC — Abuse of a dominant position — Market for the distribution of bulk mail — Direct advertising mail — Retroactive rebate scheme — Exclusionary effect — ‘As-efficient-competitor’ test — Degree of likelihood and seriousness of an anti-competitive effect)