Right now, the domainer's trade association levies an additional 20-cent surcharge on every domain that's registered--a fee that's
refunded if the buyer fails to actually claim the site after the grace period. Under the new proposal, ICANN wouldn't dole out any more refunds--which on a small scale doesn't seem like much.
But for scammers seeking to profit from domain tasting by purchasing thousands of sites at a time (and rigging them to generate ad revenue during the grace period), the cost may be a huge deterrent. As per Brian Krebs' article, under the new rules, a taster who buys 100,000 domains and keeps only one would see his or her cost jump from the price of just that one (usually less than $20) to $20,000.