Semiotics is religion, and if you work in the media industry, you should convert today.
Currently, I am, once again, browsing the books on Roland Barthes, Ferdinand de Saussure et al, and once again, I am convinced of the power of the semiotic theory for understanding modern day mass-communication.
If you work in marketing, and never read up on these topics, it is about time.

This site provides good insight into semiotics.