It is also recommendable to enter into an agreement with the advertising-partner under which the advertising partner accepts full responsibility in case of any violation committed by him. Such an agreement does not protect the provider of the program from being made responsible for the particular violation by a third party but it helps the provider to recourse to the advertising-partner.

In the case decided by the Cologne District Court, the owner of an online-shop co-operated with different advertising-partners, who installed links to the online-shop on their web pages, therefore receiving commissions for any acquisitions made through the installed links. Without the knowledge of the owner of the online-shop, one of the partners of the online-shop used registered trade marks in its metatags.

The Cologne District Court decided that the use of a third party’s trade mark without the proprietor’s consent constitutes an undue exploitation of the proprietor’s trade marks rights. The court argued that the owner of the online-shop could be held liable for the violation since the owner of the online-shop delegated the advertising for his shop to his partners. The court did not accept the online-shop’s exculpation that he instructed his partners to respect third parties’ trade mark rights, arguing that such a general instruction could only be accepted as an exculpation in case of a proper supervision of the partners.