An explaination of some of the keywords on the statistics page.

Active followers
The number of active followers. The users calendar program must have made a request to your calendar for updates within the past 30 days.

Total followers
The number of total followers. All users who have followed your calendar.

Calendar requests
When a user follows your calendar, we provide the user with an unique URL. The URL is recorded in the users calendar program and is requested frequently by the calendar program.

Follow button (views)
The number of times the "Follow button" has been exposed / viewed on your website.

Follow button (clicks)
The number of times a user has clicked the "Follow button" on your website.

Follow page (views)
The number of times the "Follow page" has been exposed / viewed.

Embedded calendar (views)
The number of times the "Embeddable calendar" has been exposed / viewed on your website.

Calendar page (views)
The number of times the "Calendar page" has been exposed / viewed.

Unfollowed
The number of users who unfollowed your calendar compared to the day before.

New followers
The number of users who followed your calendar compared to the day before.

Media / Calendar services
Which calendar service are your users using when they subscribe to your calendar.

References
If you post a link to your calendar on e.g. Facebook and Twitter and a user clicks the link, they end up on your calendar page. The reference will then be e.g. Facebook or Twitter.