The impressive growth of the smartphone market and all the buzz around Apple's App Store has marketers wondering whether they should launch a mobile application.

But it is important to know that launching a mobile application isn't a no-brainer, according to Forrester Research. Marketers need to clearly weigh the advantages of driving brand affinity, customer engagement and revenue versus costs in time and resources and the potential pitfalls of a poorly executed application.

"For the moment, most consumer-facing brands can concentrate on an iPhone application because the App Store distribution model is widely understood by consumers and has the most traction," writes Neil Strother in a Forrester Research report titled, "Is an iPhone App Right For You?"

"But pay close attention to other stores like BlackBerry App World, Android Market and Windows Marketplace for Mobile and Nokia's Ovi store," the report says. "Some have launched already, while others are expected to open in the next few quarters -- and all but Android have the near-term potential to reach a larger base of handset owners than Apple.

"As these other platforms become more friendly to application developers, be prepared to port applications to them, or provide new ones that can take advantage of unique capabilities or functionality, like Android's compass feature."

To develop and deploy successful mobile applications Forrester recommends that interactive marketers should obtain an iPhone or a competing device to make sure the company's team members are comfortable with these specialized mobile platforms before proceeding with an application.

Smartphones aren't just typical phones. They have more functionalities that just plain old feature phones.

"Mobile applications (specifically an iPhone app) aren't for every brand," said Neil Strother, an analyst at Forrester Research. "You need to understand your customers and how they use mobile devices and services, and ask whether you can provide something of value via a mobile application.

"Mobile marketers need a deep understanding of how their customers and target audiences are using mobile devices," he said. "If enough of them have smart devices and you can provide a valuable application to them, then a mobile app strategy is worth considering.

"But don't rush into a mobile app just because everyone else is doing it. Do your homework, and then plan a strategy that fits your objectives, being fully aware of the possible risks and rewards."

It is important to be able to see the phone from the consumer's perspective and understand the way most people interact with these types of phones.

"[Smartphones] have much more power and functionality than a typical cell phone, and they change the way most people interact with the Web and a variety of activities, like social networks, video and data services," the report says.

"One mobile developer described an early meeting with brand managers who asked him to develop an iPhone app: He noticed numerous older smartphones in the room but no one with an iPhone," it says. "Bad start. Marketers need to fully engage with these devices to gain a knowledge advantage."

It is also important to find out what mobile devices your audience is using.

Creating an iPhone application for an audience that is mostly using BlackBerry phones isn't going to work.

Forrester suggests that companies query some of their customers to find out how many even own an iPhone or a BlackBerry Storm or Android G1.

"Then you can make informed decisions about whom to target with an application," the report says. "Coca-Cola recognized a segment of its younger customers were on the iPhone and found that an app could be a way of connecting with a youthful audience at a reasonable price."

Forrester also recommends that brands have a long-term view of their mobile application.

It is important to plan ahead for whatever technology changes/enhancements happen in the future.

Companies should assign resources internally to make sure that the application is constantly maintained and improved.

Also, listen to any feedback customers have. After all, it is the customer you are trying to please.

"Also, consider how adaptable your application is to future marketing messages: Apps that highlight specific product features may be great for driving sales but will need to be updated as your products and marketing messages evolve," the report says.

The Forrester report also stresses the importance of measuring success of applications.

The number of downloads is important, but it does not provide much insight into actual usage.

Marketers considering a mobile applications need to be familiar with some of the emerging analytics players.

"Brainstorm ways to leverage what your company can offer through an application," the report says. "Mobile consumers want to be delighted, and a clever application can deliver both an element of fun as well as meet branding goals.

"For instance, Zippo's big idea was to turn an iPhone into a virtual cigarette lighter that often gets used by live concert-goers who in the past would have used a real lighter during an encore," it says. "The application has been downloaded more than 3 million times and rose as high as the No. 2 free iPhone application."