taking a good amount of impressions but generating relatively low earnings. For instance, in this example the “Hobbies Games & Leisure” category is taking 4% of impressions yet just making 0.7% of revenue, so you can block it. You may also experiment by blocking certain ad networks. I haven’t personally tried this, but some people claim it works.
A word of caution: Don’t block too many categories (or ad networks) or else you will significantly reduce the bid competition and will start driving your revenue down.
Pro tip: Run Optimization Experiments
You can always run an Experiment (found under Optimization > Experiments) and see if blocking your ads yields more revenue or not.
You can also test if showing 50% of your total ads vs. 100% of ads yields more revenue.
Google Adsense experiments typically last for 30-40 days, up to 100 days (depending on your experiment and traffic).
For instance, I am running the experiment of blocking certain categories, and as you can see below I already started to see some good results (unfortunately Adsense policies prevent me from sharing the exact numbers).