If you had downloaded the Feed Statistics plugin for WordPress and couldn’t use it because of an error during activation, version 1.0.3 is for you. The “Plugin could not be activated because it triggered a fatal error” message was being caused by my usage of PHP’s short open tags, which I should have known are not enabled everywhere. Thanks to Veg for the help that led to the fix.
Download the zip file of the newest version here, and overwrite feed-statistics.php in your blog’s wp-content/plugins/ directory if you downloaded an earlier version. If you’re downloading it for the first time, just copy it to that directory and activate it from the Plugin administration menu.