A lot of people want you to think so, but viral marketing actually has a much longer history, going way back before web 2.0. Before web 1.0, once know simply as "the internet". Let's start with the definition: a method of product promotion that relies on getting customers to market an idea, product, or service on their own by telling their friends about it.
There are many other definitions to be found, but going back to the root concept, promotional products could be considered the original viral marketing. Consider the power they hold.
By carrying, wearing, or using a product branded with the name, logo, and message of your organization, a person is offering their endorsement. In the terms of today's social media, they're being "fans" of your brand.
They stick around a long time, often for years if they are of high quality. Not like the billboard or magazine ad that is seen (maybe) and gone.
Even when they are not kept, they often move on to another owner. A recent survey found that the average promotional pen has seven owners before it is discarded. The marketing they do is even more effective if it includes an incentive, like this example:
They are a gift, a tangible way to say "thank you." TV commercials - uh, not so much.
The advertiser has complete control of their original target audience. Determine who receives them and how. No waste here. The pass-along audience later on is just an added bonus. With a well-conceived promotion, you can easily measure the return on the investment in promotional products.