GrowthList - A crowd-sourced list of growth hacks
Syften - Better social media keyword alerts
Q by SubStrata - Q is your email communication genius for B2B sales.
mention - Media monitoring made easy with Mention. Create alerts on your name, brand, competitors and be informed in real-time of any mention on the web and social networks
Email Marketing: A Beginner's Guide - Master email marketing with these 3 short ebooks from Drip.
Google Alerts - Google Alerts will send you email or RSS updates of the latest relevant Google results (web, news...