How the auction actually works
Highest bid wins is wrong in a way that costs money. Relevance and the landing page are the cheap levers, and the bid is the expensive one.
Almost everyone starts with the same mental model: whoever bids most goes on top. That model is wrong in a way that costs money, because it leads people to compete on the one thing that is expensive instead of the things that are free.
Bid is one of several inputs
Position is decided by a combination of what you are willing to pay and how good the system expects your ad to be. The quality part covers whether people click ads like yours for searches like this, how closely the ad matches what was searched, and what happens when somebody lands on your page.
The practical effect: a relevant ad from a well-built account can sit above a less relevant one that bids more, and pay less per click while it is there. That is the whole reason to care about structure, match and landing pages. They are not tidiness, they are a discount.
The same auction, with numbers
Illustrative, and simplified to make the mechanism visible rather than to be an accurate model of the real system.
Three advertisers compete. A bids 4 with a quality score of 4. B bids 2 with a quality score of 9. C bids 3 with a quality score of 6. If rank is roughly bid multiplied by quality, that is 16 for A, 18 for B and 18 for C. B, bidding half of what A bids, is not below A.
The price works the same way in reverse. Because you pay roughly what you need to hold position against the advertiser beneath you, a high quality score lowers what you pay for the position you hold. B is above A and paying less per click. That gap is not a rounding error; across a month it is the difference between a channel that works and one that does not.
Which is why raising a bid is the expensive lever and the only one most beginners use.
Quality score, and how to read it
The account shows a quality number per keyword, usually out of ten, broken into expected click rate, ad relevance and landing page experience. Treat the number itself as a thermometer rather than a target. The three components are the useful part because each one points at a different fix.
- Low expected click rate means the ad is not compelling for that search. Rewrite the ad, or question whether the keyword belongs.
- Low ad relevance means the ad does not visibly answer the search. Usually the ad group holds too many unrelated keywords to speak to any of them.
- Low landing page experience means the page does not continue the promise. Often it is the home page, which answers nobody specifically.
What each one looks like when it is broken
The labels are abstract. The situations behind them are not.
- A group containing restaurant stock software, restaurant stock spreadsheet and how to count stock, all served by one advert. Nothing that advert can say is specific to all three, so ad relevance is below average on every keyword in it. The fix is three groups, not a cleverer advert.
- An advert whose headline is your company name. Nobody searching a problem clicks a name they do not know, so expected click rate stays low whatever you bid.
- Every keyword in the account pointing at the home page. A visitor searching a specific phrase lands on a general page, leaves quickly, and landing page experience reflects it.
- A keyword kept because it feels important, with a click rate far below everything around it. The signal is not the score, it is that the keyword does not belong in this account.
Impression share, and what it tells you
A column worth adding, because it separates two problems that look identical from the outside: not enough clicks because nobody is searching, and not enough clicks because you are not being shown.
- Impression share lost to budget means the demand exists and you ran out of money. Either raise the budget or narrow the account so the money goes to fewer things.
- Impression share lost to rank means you are not good enough or not paying enough to appear. That is the quality conversation above, and the cheap half of it comes first.
- High impression share with few clicks means you are being shown and ignored, which is an advert problem, not a bidding one.
What this means in practice
You have two levers. The expensive one is the bid. The cheap ones are relevance and the page. New advertisers reach for the bid because it is a single number and it works immediately, then discover their costs never come down.
The order that works is the opposite. Make a small number of tightly themed groups, write ads that repeat the search back, send clicks to a page about that specific thing, and only then compete on price for the positions you still want.
Work to do
- Open your keywords and add the quality score columns, including the three components, rather than just the total.
- Find your five highest spending keywords and write down which component is weakest for each.
- For any keyword where ad relevance is the problem, count how many unrelated keywords share its ad group. That is usually the cause.
- Add the impression share columns and note, for anything underperforming, whether you are losing share to budget or to rank. They need opposite responses.