Page views represent the number of times your podcast page has been viewed.  If you drive traffic to your podcast page this number will rise and increase the chances of being one of the top 100 podcasts.

Feed views are the number of times your RSS feed has been retrieved by a podcatcher (e.g., iTunes).  The more people that access your feed the higher you will be in our top 100.

Downloads are the number of times your mp3s have been downloaded by either a podcatcher or directly from your podcast page.

Unique visitors are the number of unique IP addresses (visitors) that have viewed your podcast page on that given day.

Subscribers are the number of unique IP addresses (people) that have retrieved your podcast from a podcatcher (e.g,. iTunes) on that given day.  For example, if two people retrieve your feed via iTunes on a given day and they retrieve it 5 times each, you will see 10 feed views and 2 subscribers.