The ad auction is the process Google uses to decide which ads appear for a search and in what order they are shown. This auction happens every time someone performs a search, in real time.
When a user searches, Google first looks for all ads with keywords that match the query. Ads that are not eligible, for example due to targeting settings or policy issues, are filtered out. The remaining ads then compete in the auction.
The outcome is mainly determined by Ad Rank, which is calculated using several factors, including:
- Your bid
- The quality and relevance of your ads and landing page
- The expected impact of ad assets and formats
- The context of the search (such as device, location, and intent)
- Minimum Ad Rank thresholds
A higher bid does not automatically guarantee a higher position. Ads that are more relevant and have higher quality can often achieve better positions at a lower cost.
Because the auction runs every time a search happens, results can vary from one moment to another. This is why ad positions and visibility can fluctuate throughout the day.