The Big Book of Churn - The definitive guide to customer churn reduction
Dealflow by Micro Acquisitions - Automate your small business acquisition pipeline
Customer.io - We make it easy to send emails triggered by user behavior. Build, measure and improve your emails to activate and retain users
Mobile User Acquisition Guide - Reach your loyal users with the best strategies
Postmark - Postmark is the easiest and most reliable way to be sure your important transactional emails get to the inbox. Simply & reliably parse recieved email to JSON for your webapp.
Mailgun - A set of powerful APIs that enable you to send, receive and track email from your app effortlessly whether you use Python, Ruby, PHP, C#, Node.js or Java.