what did you choose at Delivery speed: ?
First day - 1000, second day - I increased the delivery to 1500.
Before I bought the delivery I was getting 1000-1400 organic visits per day.
My alexa went down to 200K. I started to experiment on my own - I used different FF profiles with different toolbars + adsl connect/disconnect - this way I produced 20-30 unique visits per day and the monthly ranking started to decrease by 5000-10000 per day. Once I stopped, it started increasing.
I thought that 1000 unique hits will at least stop increasing the monthly ranking.
Probably, I'm too impatient and need to wait a bit more...