Once you reserve a campaign through reach and frequency buying, your CPM is fixed, and you'll only pay the price that you established for your campaign.

If your ad set delivers more than 100% of booked impressions, we will not charge you more than the budget you've set.

There are many factors that go into determining a campaign's fixed CPM. These factors are the same whether you're buying ads in the auction or reserving campaigns in advance through reach and frequency buying.

Factors that may determine your CPM include, but aren't limited to:

• Target audience
• Schedule of dates for the campaign - when your ads are scheduled to run

  Example: Campaigns that run during a holiday or a major sporting event may cost more than campaigns that run during lower-traffic times of the year.

• Placements (Facebook or Instagram) - where your ads appear

  Example: If your ads appear only on Instagram or on both Instagram and Facebook.

• Frequency cap - the maximum number of times someone will be shown your ads.
• Creative type - the creative format of your ad determines where it can be placed and how it will be received.

  Example: Canvas ads can only be delivered on mobile.

• Objective and optimisation - whether you choose to optimise for video views or mobile app installs.

  Bear in mind that reach and frequency buying optimises primarily for reach and secondarily for your chosen objective

• Budget - the maximum amount you're willing to spend on a campaign.
• Market demand - the market demand for your target audience at the time your campaign is reserved.
• Market supply - how available and responsive your target audience is on Facebook and Instagram.
• Your own overlapping campaigns - if you're running multiple campaigns at the same time that target the same audience, it can drive up the cost of that audience.
• Creative quality and relevance - negative or positive feedback your ads received in the last 90 days.

  Tip: Learn more about designing great ad creative.

Reach and frequency buying offers highly predictable delivery of reach and impressions, but it's not a 100% guarantee of either.

* Nguồn: Facebook