57% of the US mobile audience uses mobile apps, according to ComScore. Mobile welcome campaigns originating from an app download are often a huge missed opportunity for marketers.

A well-executed welcome strategy for any new mobile customer should include a combination of channels-email, social, and mobile-to support customers' cross-channel behaviors. Don't think of "welcome" as a single message. Whether your welcome strategy covers the first 10 days or two months, as with any relationship, it takes some time to get to know each other.

Here's a sample step-by-step mobile marketing welcome campaign. We'll use a retail company's mobile app as an example, but you'll see how these basic ideas can apply to almost any industry.

Day 1
Jane Doe downloads your mobile app to her iPad. When she opens the app, she registers with her name and email address. She clicks from the app home page to your spring collection, then clicks on two different skirts. At that point, an alert window asks if she'd like to receive push messages alerting her when flash sale deals are happening. She accepts and closes the app. She then checks her inbox to find a mobile-optimized welcome email from your company.

This email:
1) Thanks her for downloading the app
2) Reminds her of the key app benefits
3) Invites her to connect with other fashionistas on your Facebook page and follow you on Twitter

Day 5
On her phone during her lunch break, Jane sees your Facebook post about with an announcement about your loyalty program and an incentive for new customers. Later that day on her laptop, she signs up for your program, which includes both email and mobile coupons.

Day 10
Jane receives a push notification about a sale you're having on spring skirts. While she waits at the hair salon, she uses your app to buy three skirts.

Since consumers don't operate in single communication channels, marketers can't afford to either. Whether you're a restaurant offering SMS coupons or a bank offering account balance push notifications, make sure your messaging channels work together to provide actual value to your customers.

Now it's your turn. What's the best mobile app welcome campaign you've seen?