Building for mobile? Don't forget that 2G is still "a thing"... a big thing, in fact. Ericsson Mobility report provides a sobering reminder: http://bit.ly/1ncn79b - a few highlights below...

GSM/EDGE-only subscriptions represent the largest share of mobile subscriptions today (over 85% of the world's population). In developed markets there has been rapid migration to more advanced technologies, resulting in a decline in GSM/EDGE-only subscriptions. Despite this, GSM/EDGE will continue to represent a large share of total mobile subscriptions. This is because new, less affluent users in developing markets will likely choose a low-cost mobile phone and subscription. In addition, it takes time for the installed base of phones to be upgraded. GSM/EDGE networks will also continue to be important in complementing WCDMA/HSPA and LTE coverage in all markets.

... In 2013, the Middle East and Africa was dominated by GSM/EDGE, which represented around 85 percent of mobile subscriptions in the region. In Sub-Saharan Africa GSM will remain the dominant technology until 2018, due to the dominance of lower income consumers using 2G-enabled handsets.

Developing regions are dominated by 2G technologies like GSM/EDGE, while developed ones are dominated by WCDMA/HSPA. LTE is rapidly being embraced by both operators and subscribers, particularly in North America. In all regions, 2G networks (GSM/EDGE, CDMA 1X) remain as fallback technology for 3G and 4G subscriptions where coverage is missing.