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December 2010

Volume 25 Number 12

Don't Get Me Started - The Secret to a Successful Windows Phone 7 App

By David Platt | December 2010

image: David PlattKiller applications sell the hardware and the OS that runs them. The classic example is Lotus 1-2-3, for which users bought the original IBM PC. The killer apps for dumb cell phones are voice and text messaging. They’ve been fantastically successful, with a mobile phone in the pocket of more than half the world’s population.

The killer app for smartphones is more elusive. Worldwide smartphone sales in 2009 were 172 million units, about 14 percent of total phone sales of 1.2 billion units.

Microsoft has just released Windows Phone 7. Many reviewers dismiss it as too little, too late. But I think Microsoft’s stolid, un-hip image (very different from 20 years ago) will play well to the much larger audience now considering the move to smartphones, provided that app developers recognize the composition of that audience and adjust their offerings to it.

Anyone who owns a smartphone today is, by definition, an early adopter. They bought an iPhone or Android because they enjoy the technology for its own sake, and for displaying status within their geek peer group. They consider the iPhone app store amazingly cool because it contains more than 100 apps that make fart noises, which they enjoy comparing and contrasting in bars with their friends.

The first app programmers resembled, and often were, their early adopter customers. They had only to build apps that they themselves liked in order to be successful. I’d bet that somewhere in the app is an Easter egg crediting the original expeller of the fart sounds and the brave anosmic souls that recorded them. But that’s not the killer app that will catapult smartphones from early adopters into the mainstream.

The next wave of smartphone adoption will come from users who value technology not for itself, but only for making their lives easier. This wave is primarily controlled by women, either on their own or as telecommunication managers for their families. They have different technology-usage patterns and goals than male users, as I wrote in my August column, “Mars and Venus” ( A killer app to them is very different from a killer app for the predominantly male early adopter audience.

My wife rolls her eyes at the farting apps. (My daughters, 10 and 7, think they’re way cool, especially when networked with the companion lighter app on another iPhone. But they don’t control the purse strings.) She absolutely loathes the iRevolver Russian Roulette app, and is underwhelmed by the iBeer drinking app—after working her job and schlepping the kids around all day, she needs the real thing. Only male geeks can pacify themselves by sucking on the corner of a plastic phone.

What is the overriding factor in the life of today’s female smartphone purchaser? She’s busy. She works a demanding job, then takes care of her kids, her pets, her parents and her in-laws, herself and her husband—very much in that order. She needs apps that deliver groceries because she doesn’t have time to stop at the supermarket; apps that schedule appointments and track medical data with the pediatrician (or geriatrician or obstetrician or vet); apps that tell her where her kids are and how late her husband’s train is running; apps that play soothing music while she waits for the kids’ gymnastics practice to end, or drown out the caterwauling at their violin lessons. In a word: tools, not the geek toys that drove the early adopters.

The next wave of customers will demand completely different apps. Developers will succeed in satisfying these customers if and only if they follow Platt’s First, Last and Only Law of User Experience Design: “Know Thy User, for He Is Not Thee.” The cool app that so impressed the first wave will leave the much-larger second wave cold.

David S. Platt teaches Programming .NET at Harvard University Extension School and at companies all over the world. He’s the author of 11 programming books, including “Why Software Sucks” (Addison-Wesley Professional, 2006) and “Introducing Microsoft .NET” (Microsoft Press, 2002). Microsoft named him a Software Legend in 2002. He wonders whether he should tape down two of his daughter’s fingers so she learns how to count in octal. You can contact him at