Stack Fallacy™ is the mistaken belief that it is trivial to build the layer above yours.
|by Ananth Sharma, FlickR (Creative Commons)
Apple continues to successfully integrate vertically down — building chips, programming languages, etc. but again has found it very hard to go up the stack and build those simple apps — things like photo sharing apps and maps.
Often the bottleneck for success is not knowledge of the tools but lack of understanding of the customer needs.
In a surprising way, its far easier to innovate down the stack than up the stack.
Google, Facebook, WhatsApp
Product management is the art of knowing what to build.