There are the ads that feel totally out of place and are animated near the text that make it unreadable. I call these obtrusive. And then there are the ads that kind of fall into place on the website and while they attempt to get your attention, they don't cause epileptic spasms and mostly can be scrolled out. I tend to accept the later ones on sites I frequent often so that they get a revenue for their effort. The earlier type makes the sites totally useless, so I fail to see the point in them.