I've seen several attempts at creating elevator pitches for the semantic web in the past, but the community's thinking has advanced a lot in the past few years and the simpler formulation of Linked Data is more readily understandable for most people. So what is the elevator pitch for Linked Data today. I am looking specifically for elevator pitches that focus on the goals and benefits, not the technology.
Jim Hendler had one of the best ones three years ago (http://swig.xmlhack.com/2007/11/30/2007-11-30.html) in which he was talking about the semantic web, but I use his elevator pitch on a slide when I'm defining Linked Data: "My document can point at your document on the Web, but my database can't point at something in your database without writing special purpose code. The SW aims at fixing that."
The more people use your data the more valuable your data becomes and everybody (including you, the publisher) benefit from this.
Information has intrinsic value which does depend on the data itself and does not change with the use of the data.
Linked Data is the best approach to maximize the extrinsic value of your data published on the Web and to leverage external contributions to improve the quality of your data itself (i.e. "Given enough eyeballs, all bugs are shallow", a.k.a. Linus's Law).
Linked Data allows the publisher to become and remain an "hub" between who provides the data and who consumes it.