For public health organizations that deal with marginalized populations—injection drug users, sex workers, ethnic minorities—using technology to engage with those populations may seem counterintuitive. Usually these groups are economically as well as socially marginalized, meaning that they may not have the financial resources to own a home computer or to have an Internet connection. Sometimes using technology seems too complicated or too expensive.
Yet there are more and more ways for people without financial resources to connect. Shared public computer access has grown through an increase in the number of cyber cafés, particularly in urban areas in the developing world. Though the cost of an hour of Internet time differs greatly from country to country, these small businesses make Internet access possible for people who could never afford to buy their own computer or pay for a home Internet subscription.
More important even than the growth of cyber cafés is the increase in mobile phone penetration around the world. This trend has been particularly marked in the developing world. Africa, for example, has seen astronomical growth in mobile phone subscribers. Text messaging (also called SMS), the "killer app" of the mobile phone, is an increasingly popular form of communication around the world. Free software, like Ushahidi, FrontlineSMS and RapidSMS are already used for public health campaigns around the world.
- In 2009 the Stop Stockouts campaign, supported by the Open Society Public Health Program, used Ushahidi, an application that maps SMS data, to reveal shortages of essential medicines in Kenya, Malawi, Uganda, and Zambia.
- The award-winning platform Medic Mobile, built using FrontlineSMS, helps health workers around the world "communicate, coordinate patient care, and provide diagnostics using low-cost, appropriate technology."
- In Guatemala, the organization TulaSalud is using SMS to monitor disease outbreaks in remote indigenous communities.
For those who are illiterate, interactive voice response (IVR) options are available through free platforms like Asterisk and FreeSwitch. Using IVR, clients can receive information through an audio menu, much like the ones used to field customer services calls in the U.S. There is actually an entire field of knowledge and practice, called "mHealth" devoted specifically to developing best practices in how mobile phones can best be used to increase health outcomes.
There is an added incentive for public health organizations to use digital technology to engage with marginalized populations. Since these groups are stigmatized, there is an incentive to provide communication options that allow the client to maintain their anonymity. Asking for information about safe sex practices via SMS or receiving a reminder to take daily medicines via text allows clients to keep their medical condition private while still gaining information and support.