Ads moving content
I know that most websites use adverts.
I can even accept the ads that cover the webpage for a few seconds and the pop-ups that cover the text you're reading.
But (and this is a really big but)…
BUT…
I despise the advertisements that move the content around on the page.
I'm a very fast reader. I can't say how annoying this is to me.
There I am reading along, and an ad noses it's way into the left margin moving the content. I have to stop what I am reading, dismiss the ad, and find my place. If I remember what the ad was for (and usually I do not), I associate it with the despite and annoyance.
What's worse are the ads that nudge their way onto the top of the page. There's no way to dismiss them and after a while they disappear. So the content moves not once but twice.
Annoying your potiential customer is not going to get you more money.