How is this plugin free?

We recently switched to a WordPress Multisite build using nginx. We decided to ditch all the nginx rewrite rules as it was complicated with nginx (yes we’re a little lazy). So we searched the internet high and low for a simple, but effective redirect plugin. And that’s exactly what Redirection does. It’s simple to import and easy to use, but has just the right amount of complexity to make it great. It’s really good. I’m actually not sure how it’s free… except out of the goodness of the authors heart.