VIRAL: 10 Things That Make You Forward E-mails

Most of these are obvious, but point number 9 is why most progressive viral campaigns aren't compelling enough to go viral.

The world's inboxes are crammed with e-mails containing jokes, pictures, movies, tests or games and which are sent to millions of people within a few hours. They're not just the preserve of skilled hobbyists, they are increasingly part of advertisers' strategies to create so-called "viral" campaigns. What is it about the best e-mails which makes them so compelling?

1. They must be funny. And, for some reason, it's a fairly coarse sort of humour which does best. Pete Brown, who runs Boreme.com, a site which collates the best viral e-mails, says: "Sport and sex do very well - really because it's the laddish humour which seems to be most popular. They work well for homemade or commercial e-mails, especially if they are crude or gross."

2. If they're not funny, then they have to be topical or somehow "shocking, clever, strange or surprising". Topical ones are usually homemade, simply because professionally made e-mails take longer to produce. A good example was David Beckham taking tips from Jonny Wilkinson on how to kick the ball over the bar, says Pete Brown. "There was a thought bubble over Beckham's head which registered simply 'ball... bar... over... win'." It worked well after England lost to Portugal in Euro 2004 - Beckham having missed a crucial penalty - because it was done quickly, he says.

3. E-mails must be a bit risky to be shocking or funny, says Chris Hassell of creative agency DS.Emotion, which makes viral e-mails for advertisers. Some advertisers will want to have a viral e-mail for people to send round as part of their campaigns, he says, but rein it back too much and "it ends up being just like a TV advert - and who wants to send that round?"

4. But not too risky. People know that employers can - and sometimes do - monitor people's inboxes. Anything that is too explicit, particularly sexually, is unlikely to be forwarded very far.

5. They must be in the right format. In the early days, most e-mails which would get sent round would be in plain text. Doctored photographs came later, but Pete Brown says the growth of movies has been marked in the last year. "That's linked to the rise of broadband, probably. But people's expectations about interactivity have increased too, and if the viral is a game, it's got to be good."

6. You've got to want to be associated with it. The whole point of sending an e-mail on to a friend is that it becomes a reflection on the sender, says Pete Brown. "A good e-mail that you pass on to your friends says something about you. You are choosing to pass on this particular joke to this particular friend. It partly says that you care about them to bother keeping open a channel of communication. It also says something about the type of person you are."

7. If it's a commercially-produced e-mail, then it's got to be for the right sort of brand. Chris Hassell thinks Ford made a mistake by distancing itself from an advert which showed a cat being decapitated by a sunroof. Following complaints from animal protection charities, the car giant said the film was an agency's idea they had never endorsed or intended for release. But Hassell says it would have done little to the brand's image among young people to have said nothing.

8. If movies have come from an advertising agency, the branding must be very subtle. "People aren't stupid - they're not going to send round something which is basically a TV advert," says Hassell. Brown adds that the e-mailed game which impressed him most was actually quite difficult to complete, and it was only when players reached the final level that they discovered it had come from Dyson.

9. Don't be politically correct says Brown. "We have never found a PC viral e-mail," he says. If it's about politicians, then it cannot show any respect.

10. Ignore points one to nine - Brown says finding the right e-mail which will go round the world depends on having the X-factor, something novel which will grab people's attention and distract them long enough from their work. [ BBC ]