Why do economists blog?

From this Economist story (via Brad DeLong (who is quoted in it):

Like millions of others, economists from circles of academia and public policy spend hours each day writing for nothing. The concept seems at odds with the notion of economists as intellectual instruments trained in the maximisation of utility or profit. Yet the demand is there: some of their blogs get thousands of visitors daily, often from people at influential institutions like the IMF and the Federal Reserve. One of the most active “econobloggers” is Brad DeLong, of the University of California, Berkeley, whose site, delong.typepad.com, features a morning-coffee videocast and an afternoon-tea audiocast in which he holds forth on a spread of topics from the Treasury to Trotsky.

So why do it? “It's a place in the intellectual influence game,” Mr DeLong replies (by e-mail, naturally). For prominent economists, that place can come with a price. Time spent on the internet could otherwise be spent on traditional publishing or collecting consulting fees. Mr DeLong caps his blogging at 90 minutes a day. His only blog revenue comes from selling advertising links to help cover the cost of his servers, which handle more than 20,000 visitors daily.