Re: Using an ugly word like "parasite" sounds like an attempt to inflame.
I studied ecology at college. A parasite can be defined as a creature which consumes from a host and delivers nothing in return. I don't know a better word.
In many ways I loathe the advertising model for web income, and arguably its a deal with the devil that we, the demos, should never have made. Admittedly in the early days it wasn't the thing it is now. We believed Google's schmuck about "Do No evil" for far too long. Worse still so did they. A bad guy who thinks he's a good guy is quite an issue. However as I choose to consume advertising supported content at home then I believe I am morally obliged to have the damn stuff occupying my screen.