For a full walkthrough, please see this overview of OCM.
As well as selecting a priority for every flight you create in OCM, you will also need to select one of two pacing options.
‘Even pacing’ – flight can hit a daily cap and stop delivering
‘As fast as possible’ – flight will keep delivering until goal is met OR indefinitely if you have selected 'sponsorship' priority (which has no goal)
The CPM rate entered here does not have an effect on the pacing or priority.