An ad for a specific user is worth a different amount to each advertiser for a couple reasons. You don’t sell something based on what it costs, you sell it based on what it worth.
Search is a bit different than display which is covered in the article, but imagine 2 jewelry companies that are exactly the same. A user searching for “necklaces” you’d think each company would bid the same amount to advertise there. But say one company is trying to raise a round of funding and needs to drive sales, they’ll bid higher to increase sales but at a lower roas. The other company is satisfied with their revenue and doesn’t bid higher.
In display each bidder has different information about a user (they may have their own data about a users behavior on their website, or it may be provided by a vendor that other bidders aren’t using). So the difference in price is largely a difference in information.
Search is a bit different than display which is covered in the article, but imagine 2 jewelry companies that are exactly the same. A user searching for “necklaces” you’d think each company would bid the same amount to advertise there. But say one company is trying to raise a round of funding and needs to drive sales, they’ll bid higher to increase sales but at a lower roas. The other company is satisfied with their revenue and doesn’t bid higher.
In display each bidder has different information about a user (they may have their own data about a users behavior on their website, or it may be provided by a vendor that other bidders aren’t using). So the difference in price is largely a difference in information.