Downstream innovation is a better implementation from an existing normalization of accepted truth. Upstream innovation is a new and better normalization of truth, subsequently yielding new renditions of downstream — an endless loop prolonging sustainability.
So, innovative thinking depends on the type of innovation in question. Downstream thinking often yields merely better economies of scale; upstream thinking requires a rethink, driven by a healthy criticism and disdain for the status quo, from which a new normalization of truth can be born.
More on the subject can be found in the Evolution of Evolution.