This document summarizes key findings from the 2018 Infinite Dial study on audio consumption trends in the United States. Some of the main points include: 1) Future podcast listeners will likely have different demographics than current listeners as podcast adoption increases. Distribution across multiple platforms will be important. 2) Growth of podcast listening on Android devices is a key to further growth, as the podcast app ecosystem on Android is more fragmented. 3) Smart speaker ownership is growing faster than smartphone adoption initially did. Smart speakers are currently well-suited for news podcasts but other formats may emerge. 4) It's important to learn from the experiences of more developed podcast markets like the US to avoid similar challenges