Great question! The only thing that counts toward your attendance percentage is how many RESERVED tickets you have used/not used.
It's basic math; if you have reserved one ticket to 10 events, but only attended 8, then your attendance percentage would be 80%.
This also includes tickets you've reserved for your guests. If you reserved two tickets for an event, but attend without your +1, then you're getting a 50% attendance rating for that event.
Additionally, if you arrive so late that our check-in process has closed, and you are not able to get scanned by our staff, this also counts against your percentage.
Things that DON'T affect your attendance percentage:
Having tickets on the waitlist that never get approved
Having available tickets that you never reserve
Deleting tickets more than 24 hours before the event
Having a show you had tickets for get cancelled
Attending a show as someone else's guest
Attending a show from the standby line
Attending a show without tickets obtained through 1iota.com
You are locked out of declining your tickets too close to an event, so be sure that if you say you're gonna be there, be there!