What is pup-under ad?

Pop under ad is an ad that is opening under currently opened browser window – so it is not desplayed to the user immidiately but only after closing or minimazing browser window used at the moment. It is also known as pop-behind ad. According to research, users reactions are better when it comes to pop-under advertising than to pop-up advertising – it is stated the cause is different, delayed “impression”.

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