The 3 Quality Score Formulas Every Advertiser Should Know

In 2009, Google revealed the exact formula that goes into the calculation of how much an advertisers is charged for a click:

It’s an inversely proportional math equation, where the cost-per-click (CPC) is equal to an unknown number that is divided by your known Quality Score. Everytime your Quality Score increases, your CPC decreases.

CPC at each Quality Score in theory.

Google has since then made changes to this formula, without divulging everything that now goes into it.

They have, hovewer, let advertisers know that the formula now includes an evaluation of Ad Extensions, even though in practice, Ad Extensions haven’t proven to be of significant influence.

In practice: When you increase Quality Score, you get added to more ad auctions automatically. Your ad is shown to more people, and in those new auctions, your competitors’ bids might be higher, in which case you might not see an immediate decrease in CPC. In those cases, consider reducing your bids when you’re using manual bidding, but if you’re happy with the additional volume, keep them as is. If you’re using an automated bidding strategy, you’re good.