Music videos are often a single relaese from an artist or band that is used to help sell more copies of the product. For example, the UK New Wave band, Ultavox, released a number of singles, which failed to make the singles charts at all. However, after the release of "Vienna" a single backed up by a music video, sales rocketed and the single sold for than half a million copies.
Extension of income
Some music videos are used to generate more money for a band and are sometimes made many years after the single was originally released, or even after the band was disbanded.
The example below, Free as a Bird by the Beatles, was an edited video made from old footage from an old demo tape some thirty years after the band had disbanded and one of the the band members was dead.
Extension of outlets
Music videos often help a band reach a wider audience through using different media such as video streaming or internet only releases. This links goes to a music video from the artist Prince which was made available only on a pay per view releases
Synergy refers to how music videos can be rleased or produced to tie in with popular TV programmes of movies.
This is Sam Smith's music video made to tie in with the James Bond Movie, Spectre.
producers’ strategies
Some producers and artists have used the idea of music videos as a way to promote their work - Prince with his pay per view videos above is one example, as is the band Radiohead with their Internet only releases and videos: