Since Junction lets you add new advertising partners in a matter of minutes, its easy to work with multiple ad networks to ensure that you're always filling your available ad space, while getting the highest value advertising.
Junction's flexible allocation rules mean that it can accomodate complex arrangements that prioritize certain advertising partners over others; for example ensuring that your in-house sales team always gets called first, before sending out the call to your ad network partners. It also allows you to group partners together; so that only certain networks have to compete on a revenue maximizing basis against certain others.