Economic value is a measure of the benefit that an economic actor can gain from either a good or service (first sentence at http://en.wikipedia.org/wiki/Value_(economics) ).

My post was comparing the current system that allows millisecond scale trading with a hypothetical one that slows trades down to something on the order of minutes. Your observation that people are willing to pay to exploit information asymmetries in the current framework doesn't address the question of how my proposed change would affect net economic value.