Greg Cox wrote:
This applies to expository material in general. Even if the primary purpose of a scene is to move the plot from Point A to B, or introduce a bit of information that will turn out to be Very Important further down the road, you want the scene to be interesting in its own right.
My favorite example of this is Peter F. Hamilton, who will often take 100 pages to get around to the first major plot event, but those first 100 pages are always totally fascinating in the mean time. Pandora's Star starts by introducing a couple important characters more than 100 years before the rest of the novel, the kind of prologue you could in theory cut, but that first chapter is a hilarious and completely unexpected little story on its own.