Editing Overlay complex (section)

===Rapid growth===
[[Urban sprawl]] accelerated the rate of expansion of [[metropolitan area]]s, and multiple split plans have caused the geographical area of a given area code in those regions to shrink, except in countries that assign shorter area codes and longer local numbers in areas with high [[population densities]]. The rapid growth in popularity of electronic devices ([[pager]]s and then [[mobile phone]]s), in addition to regular [[landline]] growth, increased demand for new phone numbers even more. Although landline growth has sharply dropped and even decreased, largely by the elimination of residential landlines in favor of personal mobile phones, it has been replaced by the even worse problem of [[mobile data|data]]-only devices ([[mobile hotspot|hotspot]]s, [[wireless modem|modem]]s, [[netbook]]s, and especially popular [[tablet (computer)|tablet]]s), which still require a telephone number for use on [[cellular network]]s even if they are unable to make or receive regular [[telephone call|call]]s.

The rise in popularity of mobile devices has added to the pressure against split plans, as an area-code change affecting the exchange in which a cellphone is based not only forces customers to reprogram their phones but also requires the [[mobile phone company|wireless carrier]] to reassign the number of every device based in those areas. While phones with a [[SIM card]] have their own [[mobile device number]] [[FOTA (technology)|updated automatically]], there is still the inconvenience of users having to update their [[contact list]]s for local family members or others who have had their numbers changed too.