In its early days, online advertising was just restricted to flashing banner ads and static pop-up windows. These days, the ads have become more creative and interactive. They pop-up and play automatically — as if viewers are challenged to shut down. They command the screen, either contracting or expanding. They move and dance across the screens. Ads are more pervasive and not easy to get past. The X- button is so tiny, and clicking it is a matter of luck. Sometimes, on purpose, X buttons are placed in the top left instead of the usual top right. Pop up ads were invented by Ethan Zuckerman  in the 1990s. These were intended to give advertisers a way to separate their message from the web page. Later, advertisers started tracking web users and served them targeted ads. Rocket Fuel and Rubicon project, autommated this process. This brought down the price of online ads. As the prices went down, the publishers squeezed more ad formats on their sites to maintain sufficient revenues to keep alive.

On desktop computers, the web pages have turned into a maze The problem is more acute on tablets and smart phones. Many publishers have shifted to HTMLS which  helps them create new ad formats.