How does ad rank?

It’s determined by how your ad ranks against competing ads. Ad rank is determined by many factors, including: The amount you bid for your keyword. For more info, see What are keyword bids. Your ad’s relevance. Your ad’s performance, based on various response signals — for example, click-through rate (CTR).
For More Information Please Refer:
https://help.bingads.microsoft.com/apex/index/3/en-us/50825#!
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