How Quora's Auction Works

On Quora, we want to deliver value to both advertisers and users with our ad offerings.

For advertisers, this means showing ads to the right users at the right time. Users, in turn, should have a positive experience seeing relevant and high-quality ads. 

We strive to deliver on these experiences, and in order to do so we hold an auction. In the way auctions commonly work, the buyers - in this case, advertisers - must offer a bid for the items being auctioned - in this case, ad placements.

Auction Factors

Our ad optimization algorithms use a variety of factors to determine the winner of an auction. This includes, but is not limited to, ad relevance, bid price, and the likelihood of a user clicking an ad. 

These factors are constantly evolving, but bid price and the likelihood of a user clicking an ad play a large role in our system. Other factors that are incorporated include:

• Feedback users submit on the ads they are shown
• The frequency users have seen ads in the past
• The likelihood users will perform a conversion action on your website

Determining Winners

For every ad placement, we consider all eligible ads from advertisers based on the budget, status and targeting specified in their ad sets.

The winners of the auction are the ads that, according to our predictions, have the highest value for the ad placement. This value is determined by a combining the likelihood of the user clicking on each ad, the bid of each ad, and the effect of showing each ad on the user experience. If more than one ad placement is available, each advertiser is only eligible to win one per page.

Choosing Ads from an Ad Set

In general, our system will favor your highest-performing ads. We take other factors into account when determining which ads to show to any given user on any given page. This includes the likelihood of engagement on the ad, your bid, as well as the user experience of showing your ad.

Your individual ads will also never compete against one another in our ad auction. For more information, please see Do my ads compete with each other?