A content delivery system, such as a Just in Time Training (JITT) system which allows the broadcast of multimedia messages to recipients or users. The JITT system identifies the multimedia capabilities as well as the capabilities of the service provider and recipient device for each user and uses this profile information to determine an appropriate messaging format to use to send the message to each user. User involvement is used to determine the functionality and content type delivery for each user mobile device. This profiling may be performed in any of a number of different ways, including smart echo, caller-ID initiated (CIDI) and SMS initiated (SMSI) profiling. In smart echo profiling, the user sends the JITT system a multimedia sample from the mobile device, and the JITT system then sends messages and content to the mobile devise using the same format. In CIDI profiling, the JITT system sends test messages in different formats to the phone number of the device, and the user replies to the message having the best audiovisual experience. The system then uses the format associated with the reply message for further communications with the user. SMSI profiling is similar to CIDI profiling, except that the user sends an SMS instead of making a call. Users with multimedia recording devices, such as camera phones, can also upload multimedia through this system for subsequent broadcast. Users with data recording devices, such as toxic gas sensors, can also upload data through this system for subsequent conversion to multimedia and broadcast.