According to a report from Marty Schwimmer at The Trademark Blog, an ICANN-related email has announced that domain tasting was down 84% in July.
July was the first month in which new ICANN rules went into effect charging domain name owners 20 cents per domain name purchased, whether or not the owners decide to keep the name. Up until July, the charge was refunded for domain names that were "returned" within five days of purchase, which led to the practice known as "tasting" -- buying up a bunch of domain names, testing them for Internet traffic, keeping the ones that were likely to result in ad revenue, and returning the rest.
Tasting is frustrating for those who have a genuine interest in actually using a tasted domain name; if the name is constantly being tasted, it becomes difficult to purchase.
I discussed this in more detail back in February in an article that was published in the New York Law Journal and a few other places, and noted that when a similar charge was levied by the Public Interest Registry, which manages domain names for the .org domain, tasting declined by something on the order of 90%.
In short, ICANN put a serious dent in the problem by adding a small but significant cost component to an activity that was formerly free.