The key person to think about is the reader. They are busy people — who normally read only one screen or a story and SELDOM read more than two screens. (A screen typically is around 300 words, though a lot depends on the illustrations.) That does not mean no long stories. As I have said before, a long story on a complicated topic can save readers time if it replaces the need to read a lot of short ones. We need to do pieces that join the dots. And everybody will always read something long of it is fascinating. Some of our most-read stories are from Businessweek. But is has to be good enterprise. Some of our enterprise stories at the moment should really have been Blasts — and a few should just have been spiked.
In general our readers either want to have a quick piece of information or something that justifies the longer read. A good rule of thumb is that stories should either be shorter than 400 words or longer than 900. You either have a simple news story or a single observation (in which case go short) or a yarn or a chance to explain something very complicated (in which case go long). But taking 700 words or 800 words to make a single point will just annoy readers.