Using too many adverts on your web page breaks the hard work you put into your design in many ways. Adverts break the flow of your content. They introduce color schemes into your web page that conflict with your choice of colors. So having too many of them on the page can produce unpleasant results.
The situation is made worse when your web page is saturated with ads that keep flashing and are looped animations. These become more distracting and annoying to the visitor. Once a visitor is in that state of mind, there is no way that the ads will attract clicks.
Another thing about the ads, especially if they are animated, is that they tend to be images which in turn slow down the load speed of your web site. Whichever angle you look at it, you are in a no-win situation.
One or two static graphical ads per page should be sufficient. Use text ads if there is need to include more than two ads on your page.