You can create huge amount of money for yourself combining adsense and Facebook traffic. But it involves more technicalities for you to scale through this arbitrage method. There are so many reason why adsense CPC low for Facebook traffic. The quality of traffic matters. If the audience from Facebook is not highly engaged or interested in your content, they are less likely to click on ads, resulting in lower CPC rates. Second, the region of your audience can impact CPC. Traffic from areas with lower purchasing power often leads to reduced ad bids from advertisers. Third, ad placement and optimization play a role. If ads are not positioned effectively on your site or if the site is not optimized for AdSense, it can lead to lower earnings per click. Finally, the type of content shared on Facebook may not align with high-paying keywords, further decreasing CPC. Monitoring these factors can help improve your AdSense performance with Facebook traffic