When the audio front line was available, it was only available in the form of discrete files that took a lot of space. The size of your post was limited. This is particularly true in the days before the broadcast 1GB of RAM. There was a time when a computer at home was limited to 16KB. However, we succeeded! Even 48K is high tech in those days. Customers should download the file, not just to hear your marketing message, so that he was dead before they hit the water. Now, however,have streaming audio, and the file size is no longer a problem. Files in streaming audio on the Internet in packets, which will be repeated when they are received and there is no need for the recipient to save anything on their computers.
Sound Package is the best way to promote your product, why give you and your client to maintain. Although the parties may agree to respond to what you say is more a sense that they are connected and are more inclined toresponse to make a purchase, or at least access your offers free trial. It's also easier to convince those who are interested in what they offer, not actually guarantee that you can not lose, and what you actually get the money back if not successful with your product.
It is much more personal than a written guarantee. Listeners the impression that you speak to them personally, even if the message was heard by thousands (hopefully)others. When the radio for the first time to the masses has been a huge success, even if the pressure is trivial, and much less expensive. Likely consequences as television has largely replaced the radio, video messages will eventually replace the streaming audio. But the video is nothing without the sound.

