Is online advertising permitted without the consent of those affected?

The lawfulness of the use of personal data is newly regulated in the General Data Protection Regulation (GDPR). However it remains unclear whether the consent of the data subjects is required for this or whether advertising is justified as a 'legitimate interest' for use in accordance with Article 6(1)(f) GDPR. To answer this question the term 'direct marketing' which is frequently used but not defined by European legislators is examined in more detail and an attempt is made to resolve the conflict between Article 6(1)(f) GDPR and Article 13 ePrivacy Directive.