General rules for advertisement creation

The following rules should serve as guidelines for creating advertisements and the compliance with these rules is an essential prerequisite to ensure the approval and launching of the ad format using our advertising system. The compliance with the rules also facilitates the whole process of launching an advertisement.

Any exceptions must always be solved individually. When dealing with special types of advertisements, it is necessary to work together with our experts from (the contact will be provided by our sales representative, who is in charge of the ad in question). reserves the right to reject advertising materials that do not meet the stated rules and conditions of standard functionality.

Unless stated differently, the following rules apply to all types of advertising formats.


The advertisement must comply with the rules of the format of chou: Image, HTML5, Text.


The size of the advertisement has to match the dimensions for the requested position. The dimension must not be smaller or larger than the defined size (unless stated otherwise in the specifications).


Some products require a specific resolution and aspect ratio (unless already specified by size) for each creative; specific values are listed in the product specification.

Maximum data size

The creatives (and all the included elements) must not exceed the set data limits for the given format.


The advertisement must not include any sounds, the only exceptions being products that support video or audio.

Design requirements

  1. Advertisement content should be horizontal, readable from left to right without tilting or rotating 180°.
  2. All the interactive functions of the banner may only be launched after hovering the cursor over the banner for at least 1 second.

Target URL

Target URL must adhere to these rules.

Delivering materials

Materials for an advertising campaign can be delivered in several ways (e.g. sent in a ZIP archive). The specific possibilities of the given product are taken into account within the technical specification of individual assemblies (see products).

  1. Advertisements delivered as an external code have to fulfill the Rules for Use of External Codes.
  2. A dynamically updated banner ad must adhere to the rules for a Dynamic HTML banner.
  3. Dynamic video ads must adhere to the External Video XML (VAST) rules.

External tracking

It is possible to track impressions of advertisements using an external system (unless stated otherwise in the technical specification). For some products, it is possible to track other actions as well (e.g. video playback from 25 % to 100 %, ad skipping, etc.).

All tracking must comply with the rules for external codes.