I'm using my MacBook for learning Japanese. Then browser is Chrome. I noticed that the battery lasted considerably less than usual. Activity Monitor told me that some processes took constantly about 10% of CPU time. I found out that those processe were PepperFlashPlayer. I had your current sales banner on 2 tabs. After removing the banner (inspect, delete node) the CPU went back to normal.
I think you should reconsider the way your banner is implemented. 10% CPU is not acceptable.