we can definitely share the detail, though it gets a bit technical, and we are tuning some the parameters, so the whole thing isn't set in stone. basically, each feedback score is weighted by three factors: buyer activity, age, and purchase price. The buyer activity weight is determined by finding the average and standard deviation of the log of the number of vendors reviewed by buyers who've ever left a review. if the log of the number of vendors reviewed by the buyer who left the feedback is greater than the average, the review has a "buyer activity" weight of the number of standard deviations above the average plus one. If it is below average, then the weight is the inverse of the number of standard deviations below the average minus one. The age weigh is found by raising 1.02337 to the power of the review's age in days and then inverting it. We got 1.02337 by making a review half as valuable after one month as one that's just been posted. The price weight comes from the following formula: 0.2*log(0.02*($price)+1)+1 where $price is in dollars. You then multiply the weights together to get the total weight for that review. Add up all of the weighted reviews and divide by the total weight to get the weighted average, then do 25*(1-avg) to get "percent positive reviews" metric. To get the seller rank, we find the averages and standard deviations of the "percent positive feedback" and the log of the total weight of the reviews for all active sellers. We then average the number of standard deviations a seller has above or below the average with a 4 to 1 weight on their average feedback over their total weight. This is a seller's rating, and we rank everyone according to this rating. There are a few little details left out for brevity, but that's basically it.