When I Activate, I see a message "bummer this site cannot activate because you clicked on a coupon"?
The reason this message appears is because retailers do not allow cash back from both Butterfly and someone else at the same time. For example, if you click on coupon site #1 and then use Butterfly, the retailer does not allow Butterfly to activate and give cash back.
But no worries! Here is one way to take care of it: you can clear your cookies from your Chrome browser and then use Butterfly on that store and you should be all set!.
See screen shots below on how to clear cookies in Chrome...