Purpose of music promo video

Music videos are created for a purpose. The main purpose of a music video is for promotion for the artist and there brand (including record labels and other originations associated with them). The exposure they can receive may provide them with an extension of income.
Music Videos can:

• provide advertisement for the artist (as previously stated; persuades audiences to buy song or album)
• can illustrate the song (highlighting deeper meanings and/or providing consumers with multiple ways to view the song)
• appeal to the a visual audience
• express emotions
• tell a story
• create/market an image/brand (allows consumers to 'buy into' the brand by purchasing goods associated with the artist e.g. dolls, apparel etc, increasing potential revenue for the artist)