Songs Existing In Films....But Missing In Cassette/CD's.

[av1979]

This seems to be norm of today's film industry. There are songs in the movie that is missing in CD's/Cassettes. Later, cassette's/Cd's with additional songs are released. Why this ?

Example Movie's are
1. Alaipayuthey (3 additional songs)
2. Bombay (2 additional songs)
3. Run (3 additional songs)
4. Kannathil Muthamittal (the additional song was never released).
5........and the list goes on.

The most recent pick is "Thavamai Thavamirudhu.." By Cheran. A Whole Song is missing in the Cassette/CD and 1 bit song.
Why Can't Directors anticipate and then release the songs ?
Are the directors trying to make the music lovers more anxious ?.....
I hope this discussion continues in the positive note such that the Director's/Producer's take into consideration this issue in the future.

Thank U.