I used to have a 468x60 top right of a site
This is what it did July 2013
Ad request: 90,599
Clicks: 683
CTR: 0.75%
CPC £0.10
RPM: £0.77
Earnings: £69.52
Same site July 2014 with the 468x60 swapped out for a 970x90 directly under the navigation
Ad request: 130,844
Clicks: 3,704
CTR: 2.83%
CPC: £0.24
RPM: £6.77
Earnings: £886.29
World of difference