By Lilly Gold

Let's first state the obvious: iPhone market penetration has been wildly successful.

Apple surpassed its goal of 10 million iPhone sales in 2008, with almost 7 million units sold within its fiscal fourth quarter alone.

Given this growth, coupled with 93 percent of iPhone owners who have added an application (TNS Compete), it is clear that brands have a new and powerful marketing channel that they should embrace.

The iTunes App Store is a marketer's dream: free customer acquisition.

Distributing an application in the App Store, while leveraging its built-in user-base of millions, means free customer acquisition.

Certainly, a brand can also attract people to add its application by promoting it on its Web site. Either way, the customers who install the application are acquired with zero marketing expense.

Even more valuable, especially in this economy, is that brands can market to their application's installed user-base again and again, without bearing the costs that they would traditionally have in other mediums, such as printing and postage fees, air-time fees and email delivery fees.

Food for thought
So, why should retailers and fast food chains pay extra attention?

They inherently have the content and information that is worthwhile to consumers, particularly for consumers on the go. And with minimal effort in developing an iPhone application, there is only upside.

Examples of basic features for retailer applications:

â?¢ Use of the iPhone's built-in GPS to locate the retailer's stores, based on user's current location
â?¢ Single tap-to-map or call store
â?¢ Display of store hours and services
â?¢ Serve special offers, discounts and coupons
â?¢ Updates on upcoming sales and store events
â?¢ Promote products via text, images, music and video -- all within the application
â?¢ Feature daily tips such as a cosmetics retailer offering tips on how to apply makeup
â?¢ Capture users' email/mobile number for additional opted-in communication

Additionally, fast food chains can offer these features to a hungry iPhone audience:

â?¢ Display menu and nutrition facts
â?¢ Single tap-to-invite friends and family to the restaurant

The goal is to get consumers accustomed to not only installing the application but also to frequently launching the application.

Kitting up
While the feature set above is certainly compelling for users and therefore a must-have for every retailer or fast food chain, the iPhone software developer kit offers tremendous potential for creative features.

Examples include:

â?¢ A branded game that involves swiping images, shaking the phone, using the phone's accelerometer. Such games keep users engaged and interacting with the brand
â?¢ Mobile commerce: make it easy for users to buy products or place an order via the application
â?¢ Loyalty program: digitize the plastic loyalty cards, and allow members to display them to cashiers via the application.
â?¢ Introduce custom polls, with option to share results of user-input. People love to see how their counterparts voted.
â?¢ Surprise specials: entice users to frequent the application by offering a special discount/coupon on one unannounced day per week. For example, a food chain could promote "Come back to our application every day because one mystery day per week, we'll be giving you a free cup of coffee!"

The possibilities of features are endless, and iPhone owners are asking for these apps.

With distribution to millions via the App Store -- and traffic from your Web site -- it's customer acquisition at its best.

And as for customer retention and ongoing marketing, these installed users have already displayed loyalty by adding your icon to their personal phone. So, serve them the content they want, and they are just a fingertap away.

True, there are many brands that have optimized their Web sites for mobile browsing, but why stop there? IPhone owners expect more.

A native iPhone application is a superior marketing channel that gives way to an ongoing relationship with customers.

This article focuses on iPhone applications, but the same principles apply, albeit with a different feature set, when Research In Motion launches the BlackBerry Application Storefront and Application Center, and when Google's Android gains wider adoption.

Lilly Gold is founder of IntuApps, a mobile application developer in New York. Reach her at