Chances are that some of you will have already experienced one of these; where a new window pops open and a 30 second long (2Mb) video advert starts playing while annoyingly sucking away your bandwidth.

Sadly a new collaboration between online ad developers (Unicast) and Microsoft is to blame. The technology is being tested on 15 sites over the next five weeks, yet is already causing annoyance among Internet users:

Most people have got used to filtering out the sales pitches in the search for useful information. But 30 second-long TV ads that appear at random whenever you click on certain websites, will be harder to ignore than pop-up ads.

Unicast's Video Commercial is a full screen online ad format that plays a 2MB, 30 second, broadcast quality video, regardless of connection speed.

The format is based on Microsoft's Windows Media 9 Series and uses Unicast proprietary pre-cached technology.

The good news is that such adverts 'could' decrease overall Internet advertising by being more expensive in the first place (somehow we doubt it).

The bad news is this bit from the BBC News Online's article - "regardless of connection speed". I personally found an extreme level of frustration when my laptops mobile GPRS connection suddenly started trying to play a video advert!

We wouldn't be surprised if dialup users also felt a strong sense of irritation towards a technology that can easily hamper any other downloads you may be doing. In reality, it may simply decrease the number of visitors to a website and increase the number using ad-blocking technology.