Social sites and blogs are the talk of the Net

Social-networking sites and blogs have come from nowhere to being among the most talked about aspects of the internet in just two years.

The larger sites have tens of millions of users and their huge popularity should prove attractive to marketers, although the best ways to advertise on these sites have yet to be agreed – most are experimenting with a combination of banner ads, sponsorship and free content. In their favour, the sites generally have plenty of information about their users, making targeting appropriate audiences more straightforward.

Until recently, MySpace was the most popular such site in the UK, although it has recently been overtaken by Bebo, according to Hitwise. Piczo claims to be the fastest growing in the UK.

There are plenty of other, more specialist networking sites outside the top ten quoted here, such as Orkut, which is owned by Google and is particularly popular among Brazilians, and the invitation-only, elitist Asmallworld.net, aimed at the affluent around the world.

For now, visiting these sites and posting content on them is overwhelmingly a youth phenomenon. According to Ofcom, seven in ten online 16- to 24-year-olds have used sites for keeping up contacts, and more than half do so at least weekly. Nearly half of 25- to 34-year-old internet users and around a third of those aged over 35 are also using these sites.

The billion-dollar valuations being touted around for sites such as Bebo and YouTube give the situation the feel of another dot-com bubble waiting to happen. But while the sector appears to have enough momentum behind it to keep growing for some time, the question that advertisers can’t answer is which sites will be able to keep hold of their audiences and which will just become unfashionable.