Alejandro Velez and Nikhil Arora were two months from graduating when one of their professors told them a very random fact that you can grow mushrooms from used coffee grounds. That little fact caught their interest and they started a business selling mushrooms.
While at farmers markets, they did an experiment to see if selling DIY kits for growing mushrooms change the customer engagement. Short answer - it did. And by a huge margin. Adults and kids were fascinated by the kit and spent much more time engaged with their products.
Here's the video where they tell the story.
Source: Startup Lessons Learned