This week saw the release of two fantastic - but very different - viral marketing videos from computer technology giants Google and Microsoft.

Microsoft went back to basics and produced a video featuring a hidden camera prank. OK ... so there's nothing particularly original there, but it's actually pretty entertaining and certainly a far cry from some of Microsoft's other much-lamented efforts. It has absolutely nothing to do with the product that it's trying to promote, Microsoft Office Ultimate software since you ask, but it's engaging, funny and surprisingly watchable. No wonder it's doing so well.

Google has taken a different approach entirely to show us exactly how fast their new-web browser Chrome is. Their new video is slick, clever, beautiful and unique. There's even a bit of humour thrown in too. It features original, intriging and completely unexpected ways to show viewers just how quick the browser is, including comparing it against lightning and even a potato gun! A massive amount of work (and money) has clearly gone into producing this video, but the result is perfect! Something that you could watch again, again and again. No wonder it's had 1.5million views already