At least in my opinion it isn’t. When I’ve wrote about PPV/CPV in the past I always referred to it is a “popup” or “popunder” but this is not what it is. You can argue that it is similar but I disagree. A popup is typically not related to what the person is visiting the particular website for (ex. a poker popunder on a movie site).
Adware on the other hand is like if you were visiting apple.com and a new window opened up an offer for a free iPhone or something related. The user experience is much much better with adware than regular website popups.
Popup = unrelated
Adware = new window with relevant info, product or service
Anyway I just wanted to make that clear in case I had confused anyone about what PPV/CPV really is…yes it’s interrupting people while surfing but for the most part with relevant information or products which could add value to their overall experience.