While a virus, in Medicine, is the smallest infectious agent, it is an extremely potent strategy in Marketing speak with similar abilities to proliferate. It is an effective means of advertising and relies on an understanding of what individuals may accept, should the price favor them.
Viral marketing by definition is any type of a marketing campaign that encourages those in receipt of an advertising message to voluntarily pass it along to friends, family and others that may be interested. [unlike a bad "virus" which one would not want to knowingly spread or pass along.]

Examples of successful viral marketing are: hotmail and their simple teaser at the bottom of all their emails that stated "Get your free private email at www.hotmail.com."

In its first 1.5 years, Hotmail acquired over 12 million subscribers.

eGroups.com [Yahoo Groups] is a free place on the Net with tools for groups to share ideas, coordinate schedules and exchange documents. It reached 4.1 million users at a faster pace than Hotmail did.

MeMail.com, the Canadian publisher with over 300,000 subscribers, has 97% of its new subscribers from direct referrals.

Every time a subscriber passes along a story or joke, attached is a subtle endorsement for MeMail.com brand.

Other forms of viral advertising are based on the idea, that people will pass on and share cool and entertaining content, which is often sponsored by an individual or company.

This is looking to raise awareness and use of a product or service. These viral commercials can take many different forms: funny video clips, interactive Flash games, images, or even text.

R.S.S. is not just a gift, but a means to propagate your brand via incoming links. It will provide content to any who wish it, but its true purpose is to infiltrate the market, virally.

Viral marketing is usually carried out by email, although it is not the same as email marketing.

Email marketing is a message that is sent out by a company to a database.

In Viral marketing a conventional database is not used. The idea is to get your reader to pass your message on to their friends, family or associates. The message then carries a powerful personal endorsement and is much more likely to be read and/or acted upon.

When a viral campaign is properly constructed and executed, you will be rewarded exponentially by the spread.

Example: 2 readers tell 2, which in turn tell 2 more and so on. It spreads 2+4+8+16+38+64 and hopefully swells to a reach massive number of readers that act on your offer or message. Ironically, even without action or direct financial participation, a mental impression can be formed through branding. While no-one will click on the large billboards that fill the landscape, the memory of it, can prompt future action with the sponsor in question. Exposure and impressions have consequences, both on and off line.

Most internet programs including mlm's initiate novices by impressing them to harvest their "circles of influences". This involves such novices telling everyone that they know, and giving the product a personal recommendation, or endorsement.

Some insist that a circle of influence strategy could spread the word to an incredible nine hundred people.

Examples of viral marketing can be seen everywhere: free email addresses, branded software, branded ipods or accessories, bravenet tools, some newsfeeds, syndication and other content, jokes (via email and offline), quotations even, anything that people want for nothing but agree to a link, like phpnuke or WordPress.

Look at the Marlboro Cigarettes campaign suggesting saving miles to purchase merchandise. Most items purchased are branded physically or by word-of-mouth, "I got it from Marlboro catalogue by saving miles".

Miles that can only be accumulated by purchasing a pack of their cigarettes.

By offering a simple download with an email or as a bonus to your offer your branded name will become known. For instance you can go here and download a great set of tools that will benefit webmasters at any level. This branded tool will benefit both the consumer and the one making the offer.

E Books are invariably information products that can be branded and embedded with affiliate links. These are often given away as free reports, but with the firm consciousness that they will be passed on to enhance a viral campaign.

Brand it, and receive widespread recognition. Embed it with affiliate links, and receive any associated revenues.

Indeed, affiliation programs could be considered to be viral in nature. While the new affiliate may not make a sale, they will surely be aware of the product and may even purchase it themselves. This does happen, incidentally.

The most powerful vehicle of a viral marketing strategy is the one that is carried to the most valuable target of all; Those that want something, and those that want something else!

Good Luck and happy viral marketing.

Judy Webb is a strategy analyst with www.EmarketingExtreme.com. If you want a powerful suite of Webmaster tools (which I still use myself), you can download it here Webmaster Tools , with my compliments.You may reprint this article if done in total, including this resource box.