WWW::Opentracker::Stats is a Perl library for retrieving and parsing statistics from the BitTorrent tracker opentracker. Opentracker provides web services for various statistics, such as the current number of peers, seeders and complete downloads for each torrent.
Opentracker is a robust and fast bittorrent tracker. It does not store anything on your disks while running, all is run in memory. From the webpage of opentracker:
One important design decision of opentracker was to not store any data persistently. This reduces wear&tear on hard disks and eliminates problems with corrupt databases.
To retrieve statistics you need to query opentracker regularly, parse the reply and store the statistics in your database so you later can follow the popularity of your torrents and detect patterns in popularity and user actions. This Perl package can be of great help for you if you are looking into torrent distribution for your content.