Blocklists help stop traffic from sources that keep sending useless or fake visits. Once you notice traffic coming from certain IPs, ISPs, or domains that don’t convert or just waste your budget, you can block them in your tracker or traffic source dashboard. Some ad networks also let you block by referrer or GEO. It’s not something you do just once. You need to check your stats often and update your blocklist as new bad traffic shows up. This helps clean up your campaign and saves money. Have you tried blocking traffic sources that didn’t give you good results?