This is cool - as long as it is just an addition to the rakeback bonuses for the corresponding levels and not a replacement of the current rakeback system. I will be very upset if it is a replacement. Please tell me it's not a replacement nor will it be a replacement for the current rakeback system.
The signature campaign is the replacement for rakeback it seems. They have have 57 shills to pay something like 6-6.5 btc per month.
1 year ago (a couple months before sig campaig):

and I think they pay more likely 10 BTC per month. 6,5 BTC per month would be only 55 in average per shill.