This summer saw the first cracks appear in networking website Facebook, as six major firms pulled ads from the its pages. The reason? The ads had appeared on a British National Party page, and Facebook couldn't guarantee that they wouldn't in future.

The problem is that advertisers want to have their cake, and eat it too. They are attempting to jump on the 'social networking' bandwagon, but the very lack of control that make these sites so appealing to Jo Public - and therefore advertisers - can work against brands.

It's going to make for interesting times, because Facebook is just one avenue that advertisers are exploring. Paying bloggers to mention products or services to their audience is another.

PayPerPost operates in this grey area, teaming up marketing departments with grassroots webcasters and paying between £3 (per mention of online business and £10 (for raving about a re-formed band like The Police) for the privilege. The question, however, is whether audiences can spot such 'advertorial' and whether they even register ads on Facebook - be they appearing on BNP or more anodyne pages? And possibly more to the point, do they care?

The smart money is on consumers wanting advertisers to display a degree of transparency. It's analogous to product placement, which is the reason why sponsorship guidelines militate against it. Still, we've all become used to luxury car brands cropping up in James Bond films. In fact, we take it for granted. So would we start to become accustomed to blogs featuring brands?

Given the immediacy of a blog, and the fact that its message is more 'personal', consumers might take against such advertising 'interference'. Brand owners are, though, experimenting with more than just blogging. Very public stunts are finding favour. One US anti-smoking campaign, for instance, stuck flags into dog mess on pavements. They featured the copyline 'Cigarettes contain ammonia. So does dog poop'. There are fears, however, that stunts which put actors or brand owners into direct contact with consumers - such as when Carbon Marketing deliberately jacknifed a lorry in central London, spilling chocolate bars from its client Nestlé on to the pavement - could rebound. All it would take is for such a stunt to cause an accident or for a consumer to suffer an allergic reaction.

So how far are brand owners prepared to go? As consumers, we're likely to say bring it on - to blog advertorial, to skyscraper ads on Facebook, even to mass sampling (Scottish & Newcastle has a 250-strong team visiting 6,000 pubs this summer discussing drinking habits with punters and buying them a drink) - but there's no guarantee that it will affect our purchasing habits one iota.