Any CSO knows that sustainability concepts are a tough sell. If videos are a return to the oral tradition of storytelling, your company should use digital media for what Free Range Studios calls "empowerment marketing."  

These dozen viral videos (in random order) struck a chord the past year, whether they attracted millions of views or simply showed off genius messaging and design.

Don't forget to check out the 10 best GreenBiz videos of 2013 to hear more from sustainability leaders.

1. The Story of Solutions

Free Range Studios is a leader in the sustainability "story wars." Its 2006 animation, "The Meatrix," hit a nerve with a message against factory farming. The Oakland, Calif.-based video mavens followed with sequels on the dairy industry and food processing.

In 2007, "The Story of Stuff" sparked their next big series with a line-drawn, behind-the-scenes tour of consumer culture. More "Story of" videos followed, about cap-and-trade, electronics, bottled water, cosmetics, "broke" and "Citizens United v. FEC." Star Annie Leonard returned in 2013 with "The Story of Solutions," below, hoping to expand the dialogue. (Hear more about message-framing from Free Range CEO Jonah Sachs.)

2. Chipotle's "The Scarecrow"

With 11 million views and counting as well as a companion app, this is Mensa-level marketing in action. Christina DesMarais took a closer look behind the scenes of Chipotle's viral marketing hit. The restaurant also offers this take at the making of the animation. 

3. NPR: Planet Money Makes a T-Shirt

Supply chains are fascinating, so why does talking about them put people to sleep? This video tells a complex story seamlessly. Start with the cotton field that produces 9 million T-shirts, and see if you can resist all five chapters. NPR's Planet Money team made this with help from crowdfunding and drones.

4. Patagonia Worn Wear

The apparel maker is notorious for renegade marketing. Remember when it told you, "Don't Buy This Jacket?" Its Worn Wear campaign (companion video below) is part of a social media effort to show off stories from customers who actually did buy that jacket.

The company wants to engage policymakers and business leaders as well as consumers with its "Responsible Economy" campaign, as mountaineer and Patagonia VP Rick Ridgeway told GreenBiz executive editor Joel Makower. Patagonia's provocative founder Yvon Chouinard starred in our most popular GreenBiz video of 2013.

5. Landfill Harmonic

Tearjerker alert. You've heard about people living in landfills who earn a living from trash. But have you heard the music this Paraguyan village makes from recycled instruments? Check out the oil can-turned-cello. The filmmakers have been working on this for several years, but were featured on "60 Minutes" in November. They seek funding.

6. New York Times: The Future of Farming

Food columnist Mark Bittman visited Kansas to meet legend Wes Jackson of the Land Institute. If you've never heard of him, see why Jackson is one of the most important sustainability voices of our time.

7. The Misfit Economy

Your company can learn a lot of good from con men, gangsters and agitators. This preview of a movie related to the upcoming book is so energetic and passionate, it will get you out of your chair. 

8. Phonebloks

Wouldn't it be nice if you didn't feel the need to get a new smartphone when one feature gets stale? That's what the creators of Phonebloks want to do with this e-waste-preventing, modular cell phone concept. No matter how far the Phonebloks effort ultimately gets, this video attracted more than 18 million views.

9. Nest Protect

Wave your rag in the air! This peppy ad makes the case for a smarter smoke detector. Its aesthetic feels inspired by Apple. Coincidence? 

Former iPod designer and Nest Labs co-founder Matt Rogers appeared on the GreenBiz stage and in several stories in 2013 for bringing "unloved" products to the home, where they promise ultimately to join the pantheon of leading Internet of Things technologies.

10. AirBNB: "Home to You"

This is one of the best feel-good commercials of the year from the sharing service that upset city leaders and made headlines around the world. Artists crafted 50 amazing birdhouses that replicate some of the coolest dwellings you'll find on AirBNB, from a lighthouse in Portugal to a teepee in Canada. Watch migratory birds flock to them as they appear on one tree at Audubon Park's Bird Island.

11. Elon Musk demos Tesla beating Audi in refueling contest

The Tesla CEO promoted his network of electric car battery-swapping stations in June to a cheering audience of Model S owners. He said he found the fastest gas station in Los Angeles to demonstrate how refueling an Audi nevertheless takes longer than switching out a Tesla battery.

12. Baby LED light Halloween costume

This bonus video has nothing to do with green business. But for any LED-loving energy efficiency geek, it's irresistible to share — and that's the very definition of a viral video.

Top image from AirBNB video