Some figures for last year.

Total listener minutes: 72585843 minute(s)
Total listening hours (TLH): 1209764.05
Total sessions: 1432219 session(s)
Average session length: 50.7 minute(s)
Total data transfer: 148.6 TB
Average data transfer: 108.8 MB
Unique listeners: 785879 listener(s)
Unique Countries: 224 countries