Multiple things combined to give this explosion. Off the top of my head : - 4G / 3G internet access became widespread, meaning you could suddenly have access t

Multiple things combined to give this explosion. Off the top of my head : - 4G / 3G internet access became widespread, meaning you could suddenly have access to a lot of internet bandwidth in each phone user's hands. - Android and iOS made it easy to make applications that are almost as powerful as what a desktop application can do, which lead to many app driven ideas. - Countries like India and China rapidly embraced the internet and have huge populations on the internet now / on the way to the internet. - Machine learning really kicked off once GPUs made deep learning viable, this allows a lot of data to be processed and insights to be obtained.