Obviously Cohen is someone going places. His story makes good copy. But it calls to mind Bush 2's efforts to bypass the elite opinionmakers in Europe to reach the masses, old Europe vs new.
We need a retail-level diplomatic capability. However, there is a chicken v egg problem here: Do the elites get power because they're part of the political system, or do they get into the political system because they have power? We may like to ignore the existing power structure in Iran, say, and help the masses rise up in a proletariat revolution, but that does not mean we can take the power away from elites. If anything, Iraq & Afghanistan demonstrate the peril, again, of bypassing the local power structures.
This retail-level approach is also inherently destabilizing, because it is a capability to undermine local power structures. In a bi-polar world, such a capability is ok because the other side is already nominally hostile. In a multi-polar world, we risk pushing potential allies into a hostile corner with this approach, notably Russia and China. [Not to say that there are deserving candidates to be hostile with, Myanmar & Zimbabwe coming to mind.]
Where the retail will be helpful is in failed states and proto-city-states. Sadly, the federal gov't is clueless on such non-Westphalian entities. A retail capability can help us map the local allegiances and power structures, telling us who would be a worthwhile ally and who to stay away from.