Even pacing spreads delivery across your dates and is the recommended default. As fast as possible front-loads delivery at a higher CPM.
Delivery is spread evenly across your flight so you have a steady presence from the first day to the last. This is the default and the base rate.
Choose Even for awareness, for always-on campaigns, and whenever consistency matters more than speed.
Delivery is front-loaded: your campaign takes as many plays as it can from day one and finishes early if the budget runs out. This carries a multiplier on the CPM because it consumes inventory other advertisers would have shared.
Choose As fast as possible for a launch, a short sale or an event where the message is worthless afterwards.
Under a total budget, pacing does not change how many impressions you get — the CPM and the budget decide that. It changes when you get them and what you pay per thousand.
Under an always-on campaign with a daily budget, Even is the natural fit: the daily budget is spent evenly each day.
The savings options on the quote card include Switch to Even pacing whenever you have chosen As fast as possible, with the exact CPM and impression difference. You can also change pacing on a live campaign; the change goes back through approval before it applies. See Edit, pause or cancel a campaign.