Another reason for low CPCs is the locaton of the trafc. Head over to your AdSense account and check out the Countries secton of your Performance Reports. If your content is in English, chances are you have the best CPC for visitors from the US, UK, Canada, and Australia, but rather low from India, South Africa, or Nigeria. The reason is mostly the lower income in these countries. If we are already in the Performance reports of your AdSense account, check out the platorms secton. I bet that you will be surprised about the huge diference between the CPC and RPM of mobile visitors compared to desktop visitors. Leverage this knowledge by increasing your mobile income with better ad placements and also try to atract visitors from well-paying devices.