A viral ad is an advertisement that achieves widespread reach because people who view it are inclined to share it among their social networks.
To go viral, an ad must offer the viewer something of value, such as information or entertainment. Beyond that general requirement, there are a number of factors that increase the probability that an ad will be widely shared. A Harvard Business Review research report recommends:
- Keep branding unobtrusive.
- Inspire joy or surprise to capture the user's attention immediately.
- Build emotional ups and downs into the flow of the content.
- Don't go over the top and make the content too shocking.
- Target users who are active on social media and likely to be influencers.
Ads can go viral for other reasons as well, not all of which are beneficial to the advertiser. A Microsoft infographic for Office 365 provided figures for the number of employees who worked in various out-of-office situations -- such as in bed, during dinner, in the bathroom and while attending a child's soccer game -- and suggested that Office 365 could increase those numbers. The ad was featured in a Washington Post blog and widely shared on Twitter, where it was roundly criticized as a promotion of overwork at the expense of work-life balance. Microsoft's misstep underlines an important requirement of creating (intentionally) viral ads: Understand your target audience. If there's a conversation about your brand, you don't want it to be about how out of touch you are with your target demographic.
See Seth Godin's TED talk, How to get your ideas to spread: