Media content delivery method and systems are provided for transmitting media content to a mobile client device in a format automatically selected from alternative versions of the media content based on one or more dynamically variable resource parameters. The variable resource parameters can include historical device and/or network performance corresponding to one or more current attributes applicable to a request for media content delivery from the mobile client device, such as a current location of the device and/or a time value for the requested media content delivery. Similar media content can thus be delivered to similar mobile client device in different formats depending on, say, the time and location of respective requests for receiving the media content.