During the online media planning phase, advertising media for each advertising medium are specified. The advertising messages can be placed on third-party websites, in search engines, and on the e-commerce retailer's own website. The frequency of contact and target group affinity play a crucial role in the effectiveness of the communication. Consequently, the relevant media data is decisive for media planning. However, the media landscape on the internet, especially in Web 2.0 services, is very dynamic, so the thematic classification and visitor numbers of an advertising medium can change within minutes [18].

Google's content network includes thousands of websites where ads can be placed 1 Greifeneder, Horst (2010): Erfolgreiches Suchmaschinen-Marketing. Wie Sie beiGoogle, Yahoo, MSN & Co. ganz nach oben kommen. 2. Aufl. Wiesbaden 2010. . Google publishes the estimated thematic classification of the websites, as well as estimated contact frequencies and approximate dependence on bids and number of clicks.

Other sources for estimating the expected frequency of contact in online media are publishers such as mediadaten Verlag with a database of several thousand booking units, categorized by topics2 o.V. 2013: Media-Daten Online. .

Furthermore, independent information services such as Alexa.com can be used to obtain information about visitor numbers and dynamics 3 o.V. (2013) Alexa Internet .

Alexa.com analyzes the internet usage of several million users and provides additional information about the popularity and networking of websites, as well as the geographical distribution, level of education, and estimated income of website visitors.

Furthermore, the evaluations of the log files of the virtual trading establishment provide information about the contacts made and may allow an estimate of the future contact frequency for the advertising materials within the e-commerce application4 Erlhofer, Sebastian (2011): Suchmaschinen-Optimierung. Das umfassende Handbuch ;[Grundlagen, Funktionsweisen und Ranking-Optimierung ; Planung und Durchführungfür Google und Co. ; Konversionsraten steigern, Google AdWords, Web Analytics ; dasStandardwerk, vollständig überarbeitet]. 5. Aufl. Bonn 2011. .