Customer.io

Customer.io is a SaaS product that provides infrastructure to send triggered emails users to improve an app’s engagement level with users.

Customer.io receives data about user behavior through on-site javascript code as well as a RESTful API.

Customer.io has rules to match users in various conditions like “hasn’t logged in in 30 days” or “has not connected to facebook”.

Users who match conditions receive emails encouraging them to change their behavior. Customer.io measures the effectiveness of those emails and allows its customers to continuously tweak and improve their triggered email campaigns.