During a recent Google+ conversation about the quality of reviews and how to improve them (more from the CS side), the issue of the sheer number of reviews seemed to be a limiting factor. Given the window of time for a conference, there is not enough time to have a dialogue between reviewers and authors. By contrast, for journals (such as Trans. IT), I find that I’ve gotten really thorough reviews and my papers have improved a lot through the review process, but it can take years to get something published due to the length of time for communication.
This points to a new fundamental limit for academic communications:
Theorem. Let R be the number of papers submitted for review, Q be the average quality of reviews for those papers, and T be the time allotted to reviewing the papers. Then
R Q / T = K.
where K is a universal constant.
An Ergodic Walk 
Clearly R is a dimensionless quantity. I propose that quality of reviews be measured in Wagners where a typical review falls in the milliwagner range whereas David’s reviews are 1 Wagner. Thus K should be expressed in Wagner/s.
Well, really it should be review rate or density, so R/T = \rho, which could be Reviews/s. Quality could be Wagners * s/Review, making K dimensionless.