Microsoft is to banish pop-up advertising, regarded as one of the most irritating forms of online advertising, from its worldwide network of MSN sites.
The US software giant has said pop-ups will no longer plague the 350 million users who visit its sites around the world after research showed consumers were no-longer prepared to tolerate the advertisements.
Pop-ups appear when users access a website, while pop-under ads are revealed when a site is closed or users log off.
They are seen by online advertisers as an easy way of attracting the attention of internet surfers, but are notoriously unpopular among users.
Microsoft announced it would remove pop-ups from its US sites last year and the extension of the policy worldwide follows a report by Forrester Research, which found that 64% of US internet users found pop-up ads irritating and 28% avoided sites that allowed advertisers to use them.
The removal of the adverts from MSN sites has already started in the UK, and sites across Europe will get similar treatment in the coming months. Other regional MSN sites are being left to decide when and how they deal with the pop-up problem.
Chris Ward, the commercial director at MSN UK, said the company was prepared to take a hit on short term advertising revenues in order to grow its business in the long term.
"We carried out research amongst our users which showed very clearly that pop-ups and pop-under ads are two of the most intrusive and disliked types of ad," said Ward.
"We also took soundings from our business partners and it's clear that a lot of them are beginning to realise there are more creative ways of getting messages across and you don't have to bash people across the head with these formats."
But some experts questioned MSN's motives, saying pop-up and pop-under adverts had become less effective.
"It's a case of shutting the barn door after the horse has bolted, because there are many tools out there to block these adverts from appearing in the first place," said Gary Marshall, the news editor of .net magazine.
"I expect the move is less to do with consumer wishes and more to do with the fact they no longer work."
MSN, which attracts over 15 million visits a month to its UK portal, already offers a service that allows internet users to block pop-ups and pop-under ads - and other companies such as search engine Google and internet service provider AOL now offer similar facilities.