Claire Beale On Advertising: A screen veteran at the age of five

When you think about it, digital years are like dog years. Only shorter. Twelve digital months are perhaps 10 years in the real world; change happens fast and fads die young.

So as YouTube celebrates its fifth birthday this month it is already a digital granddaddy, with a rich well of history and experience and oh so many embarrassing moments in its memory banks. And my God hasn't the advertising industry gorged on it, stolen from it and exploited it all in the last half a decade.

As a creative resource, YouTube is the best thing that's happened to the ad industry for decades. And rare is the adland creative who doesn't scour the YouTube library when a brief lands on their desk. Where better to look for inspiration than the place where real people go to share their obsessions. Lots of real people. People creating and sharing popular culture. So plenty of ads are better because some desperate creative has taken reference from a film lurking in the shadows of the video serving site.

But let's be frank, there are a few too many examples of ad agencies not just taking YouTube as their starting point but nicking big chunks of ideas, banging a brand on the end frame and oops, silly me, forgetting to mention that the whole thing's a shameful rip-off. The list is long. Like Berocca's, ahem, homage to OK Go's famous YouTube clip of people dancing on treadmills.

But though YouTube is grazing fodder for lazy creatives, it's also a phenomenal tool for amplifying great creative work well beyond the possibilities of an advertiser's media budget. Take one of the most popular ads of the past few years: Cadbury's drumming Gorilla for Dairy Milk. The ad ran only a modest number of times on commercial television, but enjoyed millions of views on YouTube. And that's even without factoring in the positive effects on the Cadbury brand of all the pastiches that consumers themselves posted on the site. For advertisers that manage to capture the public's imagination, YouTube offers a huge – and crucially free – audience that can be an invaluable supplement to traditional media advertising. The video site attracts a stampede of 420 million unique visitors every month and 20 hours of new video are uploaded to YouTube every minute. It's the world's third-biggest website behind Microsoft's Bing and Google, YouTube's parent.

And advertisers are slowly realising that communal sites like this are a far better commercial platform than anything they can create themselves. The web is full of deserted real estate that no one visits – all those corporate websites (yawn). Advertisers are now waking up to the idea that they need to be where people are hanging out online, on sites such as YouTube.

All of which might lead you to believe that, five years in, and backed now by the might of Google, YouTube is a sure commercial success. Oh no. It's looking pinker, but the site has struggled to work out how to make any money. Only this year is it expected to turn in its first (modest) profit.

Part of the issue has been the site's reluctance to sell ads into its user-generated content. Then last year YouTube began offering punters the chance to open up their clips to advertisers and share the revenue with YouTube. Other content providers – movie studios, TV broadcasters – are showcasing their programming, ads included, on the YouTube platform, driving new revenue opportunities for the site.

There's also plenty of potential for YouTube to ape its parent by moving into the search business, allowing smaller advertisers to bid on keywords and post their own corporate videos on the site.

One way or another it's hard to believe that YouTube won't find a way to turn an audience of 420 million (and rising) into a business that will finally begin to justify the £1.65 billion price tag Google paid.

Best in show: DDB - Marmite

They say you either love it or hate it. But even if you detest the taste, it's hard to dislike the brand's advertising. Not many brands make a virtue of the fact that they make some people vomit. Now there's a new Marmite product to promote and DDB's creative guns are firing again. This time for the launch of a Marmite cereal bar. I've tried one: they're very confusing. But after seeing this lovely series of ads, including one for Marmite flavoured fabric softener and another for Marmite perfume, a cereal bar seems rather a safe choice.