Business Week has an interesting story about the French cosmetics giant L’Oreal starting a blog to promote one of its wrinkle creams. The blog featured a fictitious woman talking about how she was using the product, and the story mainly discusses how other bloggers complained about the fictitious character, and the campaign was changed to open up the blog to real people.

What L’Oreal’s experience teaches us is that blogs can be a powerful marketing tool, but they have to be used in the right way. They need to be more authentic than traditional advertising. Nobody really minds whether Kate Moss really uses the shampoo she is advertising, but they do mind whether a blog is real or not. One of the most powerful things L’Oreal has discovered is that you can get real customers to write about their experience of the product, and that is going to create a far more powerful message.