Viral marketing causes shared experiences.

It’s cat videos with millions of hits. It’s memes that have become a part of the cultural lexicon. It’s the advertising campaign that explodes overnight. It’s Gangnam Style.

It’s viral marketing.

If you’re online in the 21st century, and if you’re reading this, it’s safe to assume you are, you’ve seen it before. But what separates these campaigns that can reach hundreds of thousands, if not millions of people in an incredibly short time, from your average run-of-the-mill marketing? What do they all have in common?

It’s actually quite simple; they generate emotions. Whether it’s making you laugh like The Old Spice Man or Evian’s Roller Babies spots, or inspiring you like Chipotle’s “Food With Integrity” or Dove’s “Real Beauty,” these spots create a shared emotion. And that leads to shares.

And it’s not just video spots. Believe it or not, way back in the infancy days of the internet, in the semi-mythological time known as 1996, Hotmail was one of the internet’s first viral successes. Because it was a free email service not linked to your internet provider, people spread the news via word-of-mouth, or more likely, email. It wasn’t necessary to sell anyone on the benefits of Hotmail, and people signed up by the thousands.

But what does this mean for you? How can you harness this power for yourself? It’s not easy, and often happens almost by accident, but here are some tips that can help create a viral marketing sensation:

Elicit an emotion.

Surprise, wonder, even anger will get people talking about your campaign. If you can move your audience to tears or make them laugh out loud, there’s a good chance they’ll share with their friends.

Be shareable and valuable.

People love to share fun items and content. For example, one of Staples’ customers has become known for giving away custom stress relievers at trade shows. Word of these cool products has spread among the people who attend the shows and they’ve seen tons of increased traffic. It’s not millions of YouTube views, but it’s still a viral hit.

Hit what’s trending.

Remember a few years ago when zombies were all the rage? Trends are your friend. Including your brand with in-vogue topics will increase engagement.

Don’t be afraid of controversy.

This won’t suit every company, but controversy is a great way to generate exposure. Certain celebrities like Kim Kardashian or Colin Cowherd have made their entire reputation by building controversy around themselves or their opinions. If this works for you, leverage it.

Be interactive.

Buzzfeed’s quizzes are popular for a reason – people love to find out which Jersey Shore cast member or AC/DC song they are. Develop fun interactive content and people will naturally share it.

At the end of the day, you can’t force something to go viral, but with some creativity and planning, you can increase the chances. And that can do wonders for your brand.