So you've invested time and resources in a branded mobile app for your company. But how do you make sure customers not only download it, but also stay engaged with it over time?

Smartphone users have dozens of apps installed on their phones and competing for attention. An estimated 82 million apps will be downloaded worldwide in 2013, with that number predicted to grow to 200 billion downloads per year by 2017. Dude, that's a lot of apps!

Push messages (also called push notifications, app messaging, or app alerts) let you send messages through your push-enabled app-even when it's not in use-to drive increased engagement.

Users who've downloaded your mobile app are already some of your most engaged customers, so keep them close and build the relationship with strategic push communications.

When tied to your overall lifecycle marketing plan, push lets you deliver alerts, deals, and discounts to increase app usage and drive in-app purchases.

Here, we provide sample messaging for each of these stages to inspire your ideas for future push messages that promote app engagement. Check out the Definitive Guide to Mobile Messaging for mobile strategy that handles the text-message channel, as well as further inspiration for push.

If you want to start building your firm foundation to push messaging success, the roadmap begins here.

App user acquisition
Before you begin sending push messages, you first need a strategy to acquire new app users. App stores are cluttered, so you need to think through other avenues for promotion. Consider promoting your app (and calling out its key benefits) in these areas:

• In an email campaign
• In an SMS campaign
• In the mail
• On your website
• On social networks
• In your brick-and-mortar locations
• On a receipt-link a QR code directly to your download page

Customers already have many apps occupying the shelf space on their phones, so always be explicit about your app's value when encouraging them to download.

For more information on the rest of the lifecycle (onboard, engage, and retain) and app notifications for each, stay tuned for the rest of the posts in this series -- or consult the Definitive Guide to Mobile Messaging.