Glossier once told Fortune that 70% of sales come from word-of-mouth organic connections. While Glossier is shaping the future of beauty by leveraging influencers, there is another company doing the same in education by leveraging teachers & families: meet ClassDojo, the world's most widely used communication app for Pre K-8 schools.

ClassDojo’s growth has been 100% organic, fueled entirely by word of mouth from just a handful of teachers in 2011 to 3.5 million users in 2012 to tens of millions of users in 180 countries today. By focusing on what its community of teachers, families and students asked for (and never spending a dollar on advertising), ClassDojo built a platform that actually suits the needs of its target audience.

From a teacher toolkit to the ability to translate foreign languages on the fly, The ClassDojo is an app that through building and listening to its community is truly revolutionizing the classroom.

The company also recently announced a $35 million Series C round, and the company boasts a Net Promoter score of 76, comparable to the world’s most-loved consumer brands including Glossier, Nike, and Disney.

Sam Chaudhary, Co-founder & CEO at ClassDojo joins me on my daily tech podcast to share the inspirational startup story. We also discuss how the ClassDojo community has been the key to their success and how they are using their community to continue growth.