There have been a lot of stats thrown at developers this week. The Pew Internet and American Life Project said that 50% of all U.S. adults have apps on their cellphones either coming from downloads or pre-loads by the carriers. Nielsen says that 43% of all U.S. adults have smartphones and that 62% of adults aged 25-44 have smartphones. This all brings us to a question all mobile developers should be asking themselves: Who are you developing for?

Coders have a habit of focusing on functionality. They see that something can be done in the environment they are working in and then go about connecting the codes, SDKs and APIs to create a dynamic app. Add some great artwork and a great app is born. Or is it? Is it a great app if nobody is using it?

Developers, coders and hackers often are not business savvy. That is one of the reasons that the classic two-person startup is born of two people: a coder and a marketer/business person. It is not just about the business person looking for ways to monetize the product (think of Eduardo Saverin in Facebook’s early days) but also making sure that the product is in front of the right eyeballs to have the highest impact.

Thinking of coming out with an app aimed at teens on the go? According to Nielsen, only 38% of teens have smartphones. What about their parents? Those ages 45-54 only have 39% smartphone adoption.

The smartphone sweet spot, and by extrapolation, the target for mobile developers looking to make money, is the adult market of college educated, urban and suburban males. We see this through Pew’s survey results. Games, social networking and news are the top apps that people spend time with. A study by analytics firm Flurry shows that 25-34 males spend the most time with freemium games and make the most transactions.

Another analytics company, Localytics, shows that people spend the most time with news apps in terms of session length but open gaming apps more frequently.

What a lot of this boils down to is Business & Marketing 101. New technology has long been marketed at young males with money to spend. For instance, look at the Verizon Droid and LTE commercials. They are brawny with a lot of flashes and lightning. These are not commercials aimed at women. On the other hand, the Apple FaceTime commercials are meant to pull at the heart strings of the older demographic and women. These are large corporations that have large marketing research departments and know exactly what demographic they want to target.

What it comes down to is that with all the analytics tools available to developers these days, there is no reason that apps and products cannot be built to take advantage of this type of data and create and app that will do will in a particular market segment.

Developers – When you are building an app, are you thinking of who will actually use it? Or is ironing out functionality more important and let the marketing sort itself out later? Let us know what your approach is in the comments.