I've never used this method so zero, and good news is I won't be effected by this new policy because if I ever have a parked domain I always just use my registrars service for this anyhow.
Actually mine is considered good, since my domain is less than a month old, and my best earning is 95 cents. But then I do blog commenting to get in traffic.
When I was just starting out I used to believe that once I reached 100 daily visitors I'd make a killing every day. Then once came the day when I first had 1.000 visitors... BOY, WAS I WRONG? I made close to a few bucks, because my niche sucked big time. Since then of course I've managed to build many sites that make hundreds per day, but that didn't happen overnight. Don't woory if it takes you some time to see the results of your work. Slow and steady wins the race