Oooooh, I can see it now: The Great Cork Shoot-Out, with different brands of cork being evaluated for their sonic qualities when used as TT mats.
Then it can go a step further. Since cork is a natural product (tree bark), within the best brands, one can look at which raw cork worked/works best for processing into cork mats. Perhaps one day we'll know the the cork from the trees from the Northwest slopes of a certain hillside in Portugal, from the 1992 harvest, when processed by Brand XYZ for industrial gasket use, makes the all-time best cork mats. Such limited quantities will be available of these "holey grail" cork, that mats made from it will be traded on a certain auction site at huge premiums over other cork mats!
Eventually, a whole cascade of quality distinctions between different mat corks will emerge. People will start discussing the subtle ways that a certain vintage rolls off the highs, or a certain grade adds deeper bass notes. Snobbism and one-upsmanship will emerge, based on who uses what cork, and how well they can talk about it. Eventually classes will be started, where social wannabes can go to learn how to properly handle and pose with their corks, how to hold them just so when examining them, how to place them properly on the platter ("Extend that pinkie!"), and what to listen for when auditioning corks. Even when they can't hear any real differences, they will learn to use the right jargon to sound as if they can and do. Gradually, this vocabulary will grow to resemble its own language, which will alternately baffle and amuse outsiders. People who "know cork" will be called "Corkies" by those who "don't get it" and those who "get it" will call others the "cork non-cognoscenti".
Eventually, counterfeits will start to emerge. Ordinary corks being passed off as more desirable ones by unscrupulous traders. There will also be cheaper brands that claim to be "just as good as" the more expensive corks. This will soon divide people into the "believers" and "non-believers", and long acrimonious threads will be generated in the Cork Mat discussion boards (
boreds-?).
"Experts" will emerge who can look at the cork surface under magnification and identify its source and pronounce it genuine or counterfeit (from a lesser year or region). Or at least they will claim to be able to do so. No one will challenge their claims, since the only ones who can verify such things are others who claim they can tell, too. No one will want to upset the cork canoe which carries their egos and incomes.
The author of the biggest "definitive" reference guide to mat cork will be feted and become the most-wanted guest speaker at audio conventions.
Various DIY methods of cork processing will emerge, such as "bathtub cork". Spoofs will emerge such as "butt-sat cork", claiming that cork is best compressed by something with a certain weight and resilience which happens to match the spoof-author's or some celebrity's buttocks, but some people will not recognize that these are spoofs and take them seriously. Then arguments will emerge over what weight, sex and shape of butt is best to sit on mat cork, and for how long. Some people --mostly those within a certain (over)weight range will offer their services at "cork-sitters", for fees. The clever ones will argue that in order to maintain the correct degree of compression, corks should be sat upon every 12 months. This will gradually be shortened to intervals of 6 months, then 3, then monthly, then weekly, as greed sets in.
People will hold Cork and Cheese parties, where they examine and compare different corks, and comment on the subtle differences between vintages and regions of cork production. The cheapest cork, the kind that no one would THINK of putting on their TT platter, will be used to line the platters of cheese.
Synthetic cork will be introduced to the mat market. People will argue over whether the artificial cork will affect the health and longevity of their vinyl. All-Organic cork will sell at a higher price than regular cork, and synthetic cork will sell widely, but be poo-pood by many, mostly people with longer hair. Certification bodies will emerge
Oh, yes, I can see it now... cork is so very human!
Always some issue or another to deal with before I can get to exciting things like cork evals 
