Mint has a plug-in called BirdFeeder that collects statistics about RSS feeds - number of subscribers, clicked posts, etc.
Unfortunately, it is not easy to install in Drupal, since the formatting of RSS in Drupal is hardcoded, so there is no template to modify. This post describes how to modify node.module to make BirdFeeder work in Drupal 6.
First, a word of warning. To change core files like node.module is generally not a good idea - anything you do will be wiped out the next time you update Drupal. If you only have one or a few RSS feeds from your site, it probably is a better idea to use FeedBurner to get the statistics. (There is also a FeedBurner module, but I'm not sure how much statistics it provides. Another alternative may be to adapt the atom.module Update: Keep an eye on the Mint module. It's still being developed, but BirdFeeder support (without changing core files) is in the plans.)
If you are not discouraged, take these steps:
Your feed statistics should now start to pour into Mint
In case you're interested in the details, these are the modifications I've made to node.module:
$namespaces = array('xmlns:dc' => 'http://purl.org/dc/elements/1.1/');
$items = '';
I added this code:
A bit further down
$items .= format_rss_item($item->title, $item->link, $item_text, $extra);
was replaced with:
Finally, these two functions where added: