Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
Content Marketing Stack - A curated directory of content marketing resources
Your Growth Hacks Aren't Working - Free new book by Steli Efti on B2B customer acquisition
Content Genie by ContentFly - Generate article ideas that will grow your traffic
Spacedoo - Short actionable marketing hacks
This Won't Scale by Drift - 40 free marketing playbooks to help you grow your business