Along with power, desire is one of the aspects of culture that cultural studies emphasizes. Indeed, desire and power are seen to lie behind the construction of knowledge. Whereas many believe knowledge to be pretty much what Plato told us (and what philosophers have always believed it to be), which is universal, accessible to pure reason, and equivalent to the other "transcendentals" such as beauty, truth, goodness, unity, and so forth, those in cultural studies reject this version of knowledge. They argue that knowledge is itself a production.
We see desire all over the place - most popular songs, TV shows, commercials, etc. focus on it. What we do not often think about are the structures that maintain it, and the ways in which we become who or what we are through it.
Freud is the theorizer of desire; Jacques Lacan is a more recent figure.