Second-author here. Details are in the paper, but yes, Google Analytics is highly prevalent. Google doesn't allow porn sites to use their ad networks so we di

Second-author here. Details are in the paper, but yes, Google Analytics is highly prevalent. Google doesn't allow porn sites to use their ad networks so we didn't find much Double-click, but it is fairly hypocritical to say "we won't show ads on porn sites" while also having no problem allowing porn sites to install your tracking software.