Audible - Audible is the world’s largest provider of premium audiobooks and spoken word content.
SwipeWell - The only tool dedicated to helping you save, organize, and reference marketing examples (so you never feel stumped).
LibriVox - free public domain audiobooks
AppGrowthLab (by SplitMetrics) - 55 app growth lessons from 30 app marketing experts
LearnOutLoud.com - LearnOutLoud.com is the web's largest resource for audio & video learning.
Marketing Examples - A gallery of real world marketing case studies. Updated every day.