Method for improved delivery of a certain content to client terminals in a content delivery network, the content delivering network comprising at least a first server and a second server, the method comprising the following steps: a) The first server storing the certain content in a first format; b) The first server analyzing the certain content and creating rules specific for said certain content to transform the content from the first format to at least a second format; c) The second server receiving a request requesting the certain content from a device, where the content has to be delivered to said device in the second format; d) The second server checking if the requested content in the second format is available in the second server and if not, the second server requesting to another server of the Content Delivery network the certain content in the second format; e) When receiving the requests from the second server, said another server obtaining the content in the first format and the rules to transform the content in the first format to a second format and sending them to the second server. f) When receiving the content in the first format and the rules, the second server applying the rules to transform the content from the first format to the second format; g) The second server sending the content in the second format to the device requesting the content; where the step a) comprises: the first server segmenting the certain content according to the first format and storing in the first server the segments of the content in the first format and where the step b) comprises: the first server segmenting the content according to the second format, the first server analyzing the content in the first and second format and as a result of said analysis, creating the specific instructions to transform each segment in the first format to one or several segments in the second format and the first server storing the instructions to transform each segment in the first format to segments in the second format and where the step of sending to the second server the content in the first format and the rules to transform the content in the first format to a second format in step e) comprises: sending to the second server, the segments of the content in the first format and the instructions to transform each segment in the first format to one or more segments in the second format and where the step of the second server applying the rules to transform the content in the first format to the second format in step f) comprises: the second server applying the instructions to transform each segment in the first format to one or more segments in the second format. a) The first server storing the certain content in a first format; b) The first server analyzing the certain content and creating rules specific for said certain content to transform the content from the first format to at least a second format; c) The second server receiving a request requesting the certain content from a device, where the content has to be delivered to said device in the second format; d) The second server checking if the requested content in the second format is available in the second server and if not, the second server requesting to another server of the Content Delivery network the certain content in the second format; e) When receiving the requests from the second server, said another server obtaining the content in the first format and the rules to transform the content in the first format to a second format and sending them to the second server. f) When receiving the content in the first format and the rules, the second server applying the rules to transform the content from the first format to the second format; g) The second server sending the content in the second format to the device requesting the content; where the step a) comprises: the first server segmenting the certain content according to the first format and storing in the first server the segments of the content in the first format and where the step b) comprises: the first server segmenting the content according to the second format, the first server analyzing the content in the first and second format and as a result of said analysis, creating the specific instructions to transform each segment in the first format to one or several segments in the second format and the first server storing the instructions to transform each segment in the first format to segments in the second format and where the step of sending to the second server the content in the first format and the rules to transform the content in the first format to a second format in step e) comprises: sending to the second server, the segments of the content in the first format and the instructions to transform each segment in the first format to one or more segments in the second format and where the step of the second server applying the rules to transform the content in the first format to the second format in step f) comprises: the second server applying the instructions to transform each segment in the first format to one or more segments in the second format.