WordPress.com stats has merged into Jetpack. Please use Jetpack instead of this plugin.
I will use it to all of my websites!
PHP Fatal error: Call to undefined function download_url() in xxxxx/wp-statistics.php on line 404
It was awesome to be able to see the statistics on my site. But it sucked that the plugin crashed my site. It messed up my home page and blog. I had to deactivate it.
WordPress.com stats covers the basics you need for most sites and blogs. You want to know where your visitors are coming from, what they are visiting, etc. Basic numbers. WordPress.com Stats is about stats, not analytics. Those are up to you. If you'd like comparative analytics, check out Google Analytics or a paid service. For free, this lets you see the traffic and popularity on your site, giving you the basics of what you need. I love it.