One great way to generate a passive income is through affiliate marketing. Now, this does depend on the size of your list. Yes, size matters when it comes to your list. Especially if you're looking to make some serious money and do it on autopilot. But, list-building takes time. It doesn't happen overnight. And you need to add value to your list or you become obsolete.
The reason to make use or virality, the ease in spreading and sharing, is however a double-edged sword. We cannot forget that in this type of campaign, a large part of the control falls into the hands of the users, and we risk the message being misinterpreted or parodied. On the other hand, a successful viral campaign can work miracles for your brand’s results.