I like that it is easy for my clientele, they can easily access their emails from any device or computer without having an app installed! The only thing i dislike about this service was there were no options of scheduling messages which would be helpful if you have clients who need different reminders at certain times during day/weekend etc..
This has been resolved now but in previous version we had those issues as well so its good news all round!! We are using Push Notifications through pushed platform with our email marketing campaigns where users receive instant alerts when new content comes up within one's account (newsletters).