I wouldn't be so fast as to consider a website spam, just because it now shows a popup, you know, just exit it, one click, however, if it were a stingy piece of popup, the kind that you need to click around and check boxes and shit, now that would have been really irritating.

Also, I am not sure if I got the exact popup that you did, but the ones that show up (as I checked) were accomplished through widget, div, meaning it is native on the website, that can also mean it is something that no adblocker is able to block.