Hot off the social networks this Monday morning is an article over at TheNextWeb about the Billion dollar economy that has sprouted up around the “free” (open-source) system that is WordPress (the image above comes from there as well). There is a solid 5 paragraph overview of how WordPress has come to be. It then goes on to outline that massive economy : from companies dedicated to selling Themes and Plugins that are either half or wholely under the GPL, to jobs focused almost entirely on designing and developing around WordPress, to, as WP lead developer Mark Jaquith points out, 24,000,000 self-hosted WordPress sites * $5/month * 12 months / year = $1.44 billion a year. That is Billion with a B.