Margins in the maturing global smartphone market continue to decline according to the latest data from market researcher GfK.

Total smartphone unit shipments increased by 7% in full-year 2015, but total sales value stayed still thanks to a 6% decline in ASP (average selling price) over the same period. In short: smartphones are, on average, getting cheaper.

This pattern was replicated across individual regions largely, with only China seeing value outpace volume, thanks largely to Apple’s continued success there. Latin America, once the main driver of global smartphone growth, is now the main drag, while North America and EMEA also registered negative revenue growth.

“Despite a record fourth quarter – and a strong performance in 2015 in general – there are mixed results across countries,” said GfK’s Kevin Walsh. “Local factors, rather than regional and industry trends, are increasingly driving markets. Diverging economic trends, device saturation, mass market adoption, politics, social change and even sport have an impact on smartphone demand and prices at country level.”

GfK also offered up its 2016 smartphone forecast, in which it anticipates ‘emerging APAC’ and Middle East & Africa being the primary drivers of both volume and value growth. With China continuing to slow and mature markets at a standstill, ASPs are forecast to decline by a similar amount this year.

“In 2016, we expect local country factors rather than global trends to impact the market,” said Walsh. “Key markets in Emerging Asia and Middle East & Africa are forecast to drive unit growth. While 2016 will be another year of global growth, it will be more important than ever for businesses to understand individual country trends and market segments.”