Bitmoji is a cool app for the fact that there is enough customization that most people are able to satisfactorily create an avatar that they feel represents them. This automatically creates some attachment to the app, and adds excitement to some mundane messages that people send on a regular basis. Bitmoji really shines in two ways. The first is that they are constantly updating their library of possible things you can send your avatar doing, including using current references to pop culture, memes, and holidays. The second is their rapid integration into already popular interfaces. You can allow Bitmoji to have a keyboard on your text messaging app, and even use it in SnapChat filters, piggybacking on existing technology as a brilliant marketing campaign.
