Abstract: Demographic information obtained from mobile devices of passengers of a public transport system is stored and subsequently used in selection of advertising content to be displayed to the users of mobile devices on an independent display. The advertisement may take the form of a video displayed on the display in the public transport system together with enriched data, for example audio content or auxiliary advertising content which is associated with the advertisement, in which the enriched data is sent to the plurality of users over a wireless network to be playable on the mobile devices. Confirmation of the advertisement being displayed is then stored on a computer database together with the demographic information associated with the mobile devices of the plurality of users to which the advertising was displayed.