Of course personalization works. On my previous job, we achieved two times action rate using trivial collaborative filtering, e.g. without using any prior know

Of course personalization works. On my previous job, we achieved two times action rate using trivial collaborative filtering, e.g. without using any prior knowledge of users except their actions history. Also, exactly half of this website is taken by popup "Subscriiibeee!!" pane without close button. What a waste of time.