The article explores how much competition is needed in auctions for simple auctions to make more money than the best possible revenue. The researchers found that in dynamic auctions, having at least three times the number of buyers is needed for a second price auction to earn as much as the best dynamic auction. They also discovered that just one extra buyer is enough for a VCG auction to be a good approximation of the best revenue. This is the first time such guarantees have been provided for auctions with correlated stages.