One of the best ways out there to get a more engaged existing user base for your app is through email marketing. Although 84% of all emails sent are spam, email marketing is one of the most effective marketing tools out there. This effectiveness is, of course, only in place when you have a person’s explicit permission to send them emails. With an app it’s as easy as pie to get people to sign up for your newsletters, tips & tricks, special offers and all other messages you want to send to the users of your app. Follow one golden rule: always ask for permission!