A study on online advertising by Jakob Nielsen shows that web users dislike pop-ups the most and also tend to dislike websites that employ them.

According to the study, users who are deceived into clicking on a misleading ad might drive up your CTR, but they're unlikely to convert into paying customers.

Here are a couple of things to avoid on your website if you really want to retain visitors and keep the advertising dollars coming:

* Pop-ups (and even pop-unders)
* Slow load times
* "Teasing" links, misleading categories, and other elements that trick users into clicking
* Content that doesn't clearly state the site's purpose or what a particular page covers
* Content that moves around the page
* Sound that plays automatically

Users tend to appreciated ads that indicate what will happen if they click on the link and ones that clearly identify themselves as advertisements.

Source: The Most Hated Advertising Techniques

Via: Pop-up Windows not allowed on Adsense Pages