Many of them can't help themselves.

I used to have long conversations with frontend developers that "no, when I log on I don't want to be forced through a look-at-the-new-feature-we-made" sequences. And then they went ahead and did it anyway. And usually whatever flag they tried to set to make sure you only saw it once would malfunction, so next time you'd get to click through it all over again.

(If you want to tell users about new features, show a unread flag on a notification icon and make it a one-click affair to make it go away. Don't get in users' face with stuff they don't want)