Shawn's like Google, he'll never tell. The he'll just start updating it at completely random times and all of the weight adjustments will seem out of whack and we'll all say it's broken It's the next Google
LOL... I don't need that extra stress in my life... soon we'll start seeing threads pop up on a bunch of forums: CO-Op network update!! I broke 100k! LOL
All Shawn needs to do is start displaying the weight using a bar like the Google toolbar and we'll be in business. Who cares about PR, what's my ANW?
People who participate in the ad network are assigned a weight based on a number of factors. The higher the weight the better (more impressions within the network). I believe Shawn is still manually updating the weights every so often until it's 100% automated.