This lets you design devices with a fairly powerful CPU, but still stay within the bounds of cheap manufacturing (2 or 4 layer boards, >0.5mm pitch, 6/6mil trac

This lets you design devices with a fairly powerful CPU, but still stay within the bounds of cheap manufacturing (2 or 4 layer boards, >0.5mm pitch, 6/6mil traces, no BGAs). These kinds of modules are enabling lots of new appliances that were too difficult to build before. I'm saying "these kinds", because lots are appearing, for example the Samsung ARTIK line or boards produced according to the 96boards.org standards.