The key with viral ebook marketing is to create a great ebook, and then make sure it gets around. You have to give it away a lot - and give it to people with email lists of their own - and ask them to give it away.
Ideally, you will include in the ebook, links, either to your own squeeze page, to other products you own, or to affiliate programs that might be of interest to the reader of the ebook.
However, one of the best ways to build a list fast using a viral ebook, is to require registration of the ebook before they can open it or download it. Basically, instead of giving away the pdf ebook itself, you allow others to give it away by giving them a squeeze page of yours that gives it to them free.
Another method of viral ebook marketing is to use a viral pdf generator. What that will do is allow the new recipient of the ebook to brand it with their own links to affiliate products - giving them more incentive to distribute the ebook. However, at the very beginning of the ebook, you can offer a special free gift to anyone who registers the ebook. To register the ebook, they go to one of your squeeze pages and opt in to your email list.
Unfortunately for the beginner, one without name recognition, this is probably not the best route to go to create traffic. Although when an ebook goes viral, there is a massive amount of traffic associated with it, most do not go viral. So in most cases, there is no real return to your efforts.