Some time in 2013, a video series revolving around a similar concept began appearing around the Internet. This is often called "viral" media, or "spreadable" media, but it's important to recognize that no one knows precisely where it began or how it began to spread. In other words, it was by the people and for the people. However, it was guided heavily by the influence of a set of nonprofits (like the ALS Foundation) intent on contextualizing and integrating the experience into their brand. It ended up raising well over $200 million. The video series was first called the "cold water challenge," and then (as you've already guessed) became the "Ice Bucket Challenge." 

So what made the IBC successful? A series of things:

1. It was accessible. Everyone could do it.
2. It was funny. There's nothing like making a fool of yourself, and then challenging someone else to do it too.
3. It was spreadable. The videos were short and hilarious.
4. It was contextualized. The ice water was meant to simulate the feeling of tension for those with ALS and similar conditions.
5. It connected to celebrities. People in the spotlight were able to advocate for change without doing much.
6. It integrated well into existing campaigns, especially ALS Foundation's campaigns, without being explicitly monetized.

These factors are easily replicated for all sorts of issues. Does this mean it's easy to create a viral video? No. But drawing from your community and networks, and involving them in the process, makes the chances far more likely. Following the above steps will make your chances much greater, and the more you try, the more you're likely to succeed. Remember, engagement is about giving and sharing, not taking or selling.