The dawn of Web 2.0 and the flourishing social networks and online communities it has spawned has, for many, upped the stakes in the marketing and advertising world. More than anything, online social networks make it possible for people to communicate - whether this is on a social or a business level. In particular, the technique of viral marketing benefits from using social networks as a platform, as is made clear from the success of the world's most popular social sites.

From the early days of Friends Reunited to the modern success of the likes of MySpace, Bebo and Facebook, social networks have always presented advertisers and marketers with a burgeoning audience. However, using the internet to market a product isn't something that began with Web 2.0, strictly speaking: the late 1990s show clear evidence of people using the internet as an effective tool of social marketing.

In 1999, for instance, the independent horror film "The Blair Witch Project" used the unprecedented tactic of using its official website to suggest that the film was an actual event. The movie, presented as a piece of amateur documentary footage about three teenagers who disappear while making a film about a local legend, had only a budget of $25,000 but went on to gross over $248 million worldwide - primarily as a result of its successful and unique online viral marketing campaign.

Today, new and upcoming bands need no longer seek a record deal in order to gain fame and popularity: MySpace's rapid word-of-mouth circuit ensures that any band across the world that's gaining attention does so by appealing to a core group of MySpace users and waiting for them to tell their friends.

The recent launch of the Facebook Marketplace platform also suggests that marketers are becoming increasingly tuned to the benefits of viral marketing via social networks. Facebook Marketplace allows users and businesses to post free classified ads on the site, while Facebook Platform is an API that allows for the development of applications to be placed on the website.

The most recent Facebook success story comes in the form of iLike - an online music community that was struggling to get its name noticed only a month ago. But today, directly as a result of its utilisation of Facebook Platform, iLike is the fastest growing digital music application on the web, with over one million new users per week and information requests from record labels coming in every half an hour.

However, social networks aren't just a great viral marketing tool - they're also a fantastic way for marketers and advertisers to share information and tips with one another. For example, if you're in the marketing industry, seek out an online marketing communications community that befits your particular line of interest. You'll find blogs from magazines and leading marketing experts, as well as active discussion forums and specialist news posts on which you'll be able to comment.

Moreover, online marketing communities can be a great place to make new contacts within your industry and, if you're looking for a new job, can provide you with invaluable sources of information about the best companies to work for and who's recruiting right now. After all, viral marketing can work on marketers too!