In the past three months Coca-Cola, Starwood Hotels, Honda, Nokia, Benetton, Ducati, Guinness and HSBC have all caught blogging fever. Sure, there's an element of trendiness to say you're a blogger or podcaster, but their objectives are tried and true marketing techniques. Blogs and podcasts embrace successful elements of direct marketing by building a dialogue with consumers, as well as extending the brand image. This social media enables a company to build a community around its brand and invite consumers inside the CEO's office.

On 10 March the Italian motorbike brand Ducati launched a blog at http://blog.ducati.com where CEO Federico Minoli vowed "to write openly about what's going on at Ducati". In the first three days his posts generated 99 responses. Motorbike enthusiasts from Thessalonica to Daytona Beach began chatting with other about the specs on their bike and firing off questions to Minoli about when new models will hit production.

The blog commentators seemed most pleased that Minoli was a motorbike enthusiast. As one wrote, "I thought CEOs are made only for boardrooms, but apparently not anymore. We're glad that everybody now has access to his thoughts."

South African vintner Stormhoek Winery had a different marketing objective. A three-year-old brand, Stormhoek wanted to crack the ultra-competitive British wine market in an upscale way: by educating customers on the finer points of wine freshness. It was a message too wordy for a single label, so it launched a blog at stormhoek.com. With the help of its own publishing platform, the vintner could write about the merits of its grapes and reach customers directly.

From the blog it had 200,000 hits a month, with co-founder Nick Dymoke-Marr claiming it made it easier to get in front of key marketers and buyers.

The overriding consumer appeal of blogs is that they appear authentic. Blogs are bringing a level of humanity back to the faceless corporation.

Unless you get it wrong, that is, like Coca-Cola and L'Oréal did. Both launched blogs authored by fictional characters who did no more than parrot the company line. Bloggers quickly saw through the fakery and lambasted the companies for failing to take them seriously. Last year the backlash forced Vichy, part of L'Oréal, to withdraw a blog designed to market an anti-aging cream because the photo of Claire, the fake middle-aged blogger, showed a picture-perfect young model without any wrinkles.

But instead of retreating behind another ad campaign, Vichy consulted with French bloggers and launched a new blog replete with actual Vichy employees. It used the blog to canvas the public on how the company could better interact with its customers. The comments were forthright but honest and the company obtained valuable feedback.

Inviting comment on your brand from Joe Public might not be for the faint hearted. However, as more corporations are realising, customers are already conversing online about their brands. And when others are talking about you, it's much better to be part of the conversation than left out of it.