A method of providing supplementary information to a first client device for presentation using the first client device, the supplementary information being related to multimedia content, the multimedia content being provided to a second client device for presentation using the second client device simultaneously to the presentation of the supplementary information, the method comprising: acquiring, by one or more processors (32, 36) of a service module, the multimedia content from a content provider; acquiring, by the one or more processors (32, 36) of the service module, the supplementary information; determining, by the one or more processors (32, 36) of the service module using the supplementary information, a genre of the multimedia content; determining, by an activity-detection module, an activity level for at least a portion of the multimedia content using the determined genre of the multimedia content to guide the activity-detection module to process the multimedia content to determine the activity level, the activity level being indicative of a level of activity that occurs within the audio and visual content of a scene corresponding to the at least a portion of the multimedia content; assigning, by the one or more processors of the service module, using the determined activity level and the acquired supplementary information, some or all of the supplementary information to the at least a portion of the multimedia content for which the activity level has been determined, the amount of the supplementary information assigned to the at least a portion of the multimedia content being dependent upon the activity level; and providing, by the one or more processors (32, 36) of the service module, to the first client device, the assigned supplementary information, thereby providing supplementary information to the first client device. acquiring, by one or more processors (32, 36) of a service module, the multimedia content from a content provider; acquiring, by the one or more processors (32, 36) of the service module, the supplementary information; determining, by the one or more processors (32, 36) of the service module using the supplementary information, a genre of the multimedia content; determining, by an activity-detection module, an activity level for at least a portion of the multimedia content using the determined genre of the multimedia content to guide the activity-detection module to process the multimedia content to determine the activity level, the activity level being indicative of a level of activity that occurs within the audio and visual content of a scene corresponding to the at least a portion of the multimedia content; assigning, by the one or more processors of the service module, using the determined activity level and the acquired supplementary information, some or all of the supplementary information to the at least a portion of the multimedia content for which the activity level has been determined, the amount of the supplementary information assigned to the at least a portion of the multimedia content being dependent upon the activity level; and providing, by the one or more processors (32, 36) of the service module, to the first client device, the assigned supplementary information, thereby providing supplementary information to the first client device.