Maybe I should have said that some tricks are slow to deploy. Sometimes the publisher only embeds an image form the tracker (the famed "tracking pixel"). Getti

Maybe I should have said that some tricks are slow to deploy. Sometimes the publisher only embeds an image form the tracker (the famed "tracking pixel"). Getting lots of sites to change that to script is a pain. Sometimes they need to deploy new server-side tech for a workaround. For the recent CNAME cloaking trick, they have to get sites to modify their DNS and change what URL they embed script from.