I found there are some podcasts on bitcoin, they are very good stuff to promote bitcoin.
I am listening some of them now on my way to work.
The "Bitcoin Crypto Mastermind" hosted by Tai Lopez is a good one, here is the link (http://castbox.fm/channel/Bitcoin-Crypto-Mastermind-id1108208)
The "CRYPTO 101" is also a good one. (http://castbox.fm/channel/CRYPTO-101-id973054)