Last night, Laurie Penny tweeted: "Like many others I know, I'm trying to find a way of making it more viable to produce more of those longform, deeply-researched pieces."

Gawd help us. When will people realize that brevity and concision are virtues? I ask for several reasons:

1. Longform writing is narcissistic. It presumes that one's writing is so brilliant that it deserves to deprive readers of time they could spend doing other stuff - not least of which is reading other good things. And it is correlated with the notion that one's ideas are so complicated and nuanced that only thousands of words can do them justice; this ignores the fact that a few qualifiers - "mostly", "to some extent", "in this context" etc - can signal nuance.

2. Don't reinvent the wheel. Most stuff worth writing has been written already. Just link to it.

3. Anecdotes are not data. Stories add to the wordcount and give "colour", but they often beg the question: are these stories representative? Simply linking to data is more accurate, and briefer.

4. Assume your readers are intelligent. (Granted, this is a weaker assumption for me than it is for those condemned to write for the Guardian or Telegraph). They don't, or shouldn't, need everything explaining. They should also be able to see objections to what you write, and objections to those objections. And if they can't, ignore them.

5. There are diminishing returns to length. If readers think you're a prat after 500 words, they'll not change their mind after the next two thousand. In fact, there might be negative returns, simply because your gems are hidden. Laurie hides away a brilliant line - "Sometimes when you're dying of thirst, you have to drink the Kool-Aid" - in thousands of words of ho-hummery. And none of the screeds written about Ed Miliband have affected my opinion of the man so much as a single paragraph from Steve Richards (again, hidden in unnecessary words).

It was Mark Twain, or maybe Blaise Pascal, who said "I didn't have time to write a short letter, so I wrote a long one instead." He was speaking an important fact about writing - that it consists in leaving stuff out. As Gabriel Garcia Marquez once said, writing should be like an iceberg - "supported below by seveneighths of its volume."

Regular readers might have spotted that I am rarely mistaken for Twain or Marquez, but I try to follow this; I have a rule on this blog to never write more than 600 words.

Of course, this rule cannot survive in the marketplace. Commissioning editors want long pieces in part because readers are apt to equate length with intelligence and seriousness. The MSM doesn't want links which direct readers away from their sites. And if we are paid by the word we'll produces thousands of bad ones rather than a few good ones. But perhaps this only shows that, as Niklas Luhman among others has pointed out, there is sometimes a tension between good communication and commerciality.