As a follower of many blogs, I am commenting from a reader's perspective rather than the blogger who is trying to monetize. Let me start by saying that I'm not talking about your specific site; rather I'm speaking in a general sort of way.
I've seen great blogs with a small space for ads suddenly covered in all kinds of advertisements in all kinds of places. When there are numerous pop ups, ads that cover the pictures, ads that fill the spaces between paragraphs, on headers, footers, sidebars, and so many other places that it makes it difficult to read the post content on a computer and nearly impossible to view it on a mobile device. I've gotten so frustrated trying to read what looked like an interesting post that I've given up the battle and walked away.
There is no revenue when people stop coming to your site. Everyone wants to make money, but if a blog has too many ads, then it loses a certain amount of visual integrity and classiness. It starts to resemble a car that's covered in bumper stickers rather than a sleek BMW or Porsche.
As +Chef Dennis Littley
said, this is a way for bloggers to maximize the value of sponsored posts. Perhaps limiting the amount of ad space will also increase its value.