Good idea, though I'd add another metric: market reach, in terms of, for the case of social media, users.
This might have other metrics though -- sources / sellers, for a market or middleman entity, some weighted metric of business customers for b2b suppliers (such that an F-10 company weighs more than an F-10000 company). For physical management (say, commodities), total tonage moved. Et cetera.
This might have other metrics though -- sources / sellers, for a market or middleman entity, some weighted metric of business customers for b2b suppliers (such that an F-10 company weighs more than an F-10000 company). For physical management (say, commodities), total tonage moved. Et cetera.