The package size for mobile chips is also shrinking (and presumably die size as well). For example the Skylake Core M package is half the size of the Broadwell

The package size for mobile chips is also shrinking (and presumably die size as well). For example the Skylake Core M package is half the size of the Broadwell Core M according to Wikipedia (die size is listed as TBD). Aside from the size benefits for board layout, a smaller die would let them get more CPUs from a wafer while a lack of competition in the mobile x86 space lets them charge the same amount for each one.