How does the Meta Ads auction work?
- What happens if you set a low conversion bid in a highly competitive market?If you set too low a conversion bid (e.g., $2) in a highly competitive market where the actual cost per conversion is higher (e.g., in the USA), your ad may receive no impressions or very few.
Why does this happen?
- High competition: Other advertisers are willing to pay more for the same target audience, and their Total Value in the auction will be higher.
- Inability to meet your bid: Facebook won’t be able to optimize impressions to keep the cost per conversion within $2. In such cases, it won’t participate in auctions requiring higher bids.
- The algorithm will try to find less competitive segments of your target audience (e.g., users with lower conversion probability or less popular time intervals) to try to stay within your budget.
- However, such impressions may be less effective because a target audience with low conversion probability likely won’t bring desired results.
- Why is the cost per impression (CPM) high in auctions with narrow audiences?Targeting specialists and entrepreneurs often use custom audiences in their tests (customer lists, website users focused on specific actions, etc.), which can increase the cost per impression due to limited audience size.
CPM (cost per 1000 impressions) for narrow audience segments tends to be high due to several key factors related to competition, user availability, and Meta Ads algorithms.Why CPM increases for narrow target groups:
- High competition for narrow audience attention
- Limited impression availability
- Higher targeting costs
- Ad Fatigue problem
- Facebook algorithms and impression “value”
- What happens if I win the auction as an advertiser but the user doesn’t see the ad?If you win the auction but the user doesn’t see your ad, you don’t pay for this impression. Here’s how it works:
- You only pay for actually viewed ads
- Facebook only records viewable impressions
- Facebook redistributes your budget for showing ads to other users
- Conditions for counting impressionsFor static ads:
- Must be visible on screen for at least 1 second
- At least 50% of ad area must be in visible screen area
For video:
- Must be visible on screen for at least 2 consecutive seconds
- 50% of video area must be visible
- Ad display order in media contentThe order is determined by:
- Auction system
- “First is best” logic
- Content personalization algorithm
- Ad rotation
- Geographic and time factors
Example of priority order:
- User opens feed
- Algorithm first shows organic content
- First highest-rated ad is inserted
- Organic content and ads alternate with decreasing priority
Autor: Nikolas Shevchenko
