How often does the AdWords system run an auction to decide which ads to show on the Google search page?
A) Once every two hours for a given keyword.
B) Once every 24 hours for a given keyword.
C) Every time a user enters a search query.
D) Every time a new advertiser adds a keyword to an account.

Question

Quizplus · Accepted Answer

The AdWords system runs an auction every time a user enters a search query to determine which ads to show and in what order.

How Often Does the AdWords System Run an Auction to Decide