I had no familiarity with the concept of "phatic discourse" before reading this fascinating piece, which relates it to the current state of British comedy. Apparently it's the everyday language we use which has no real communicative purpose, other than as social lubricant. "How are you?" for example.
The author argues that the current spate of catchphrase-driven British sketch comedy -- Little Britain, in particular -- serves as a source of this odd form of communication. Instead of being, you know, funny, the series simply offers chunks of material that we can understand and relate to, then repeats them until their real meaning is one of recognition, rather than surprise. We can repeat the catchphrases to our compatriots, having the same effect as the show.
As a thesis, it's a bit of a stretch, but it's a wonderful idea that captures some important qualities of a certain type of comedy.