Because I could use it and I would think it would be very popular with others to use.
A gif animation with sound. It needs to be pasted and would display like any gif.
In other words if I paste the gif animation with sound in a email it the image would display and the sound would play with out having to open in Windows Media Player or any other program.
example a 'Smiley Button' with a simple sound. And copy,paste, play/view just as the Smiley Button does.