Disabling third-party cookies
Another thing you can do to stop ad cookies is disable third-party cookies in your browser — though installing Disconnect or Ghostery has much the same effect.
In Safari, they’re actually disabled by default. In Chrome, you’ll have to go to ‘Settings > Advanced > Privacy and Security/Content Settings > Cookies’ to find the switch to turn off third-party cookies. In Firefox, you have to go to ‘Options > Privacy’ and select use Custom settings for History to see the option to disable them. In Edge, go to ‘Options > Settings > Advanced Settings’ and select the option to ‘Block’ on ‘Third Party Cookies’ under ‘Cookies’.