Is there a benefit to cap frequency over using chain of networks?

I have yet to try capping the frequncy ads appear to visitors from various cpm networks. Instead I use a chain of 3 or 4 networks with the first network having the highest cpm payout and on down the line. In this type of setup is there a benefit to capping the frequency of ads displayed from each cpm network? If so I will look into setting up a system via google admanager or openx. (About 30-40% of my visitors are US based and most of these networks deliver only to the US visitors).

See original post by ubuntu2006