I had a couple people ask me about this. I’ve given this talk a couple times, and I thought the community (especially the evangelists) would appreciate a “what is Blockstack” slide deck 
Link: https://docs.google.com/presentation/d/16HcYz8Jxq-w6HLFX1PTwLNmZJWZiVyeNCWdKkVxS_JI/edit
Recording: https://zoom.us/recording/play/P9MTlay3ck1jXkLhkFlQqxtKV5xoo4gUkY5YQPmVQl84iz0kPC1-Dm2136JneZC1