How Do Google Ads Work? The Auction, Ad Rank and Costs Explained

Google Ads works through an auction that runs every time someone searches. Advertisers choose keywords and set bids, and Google uses Ad Rank to decide whether each ad can show and where it appears. Ad Rank looks at your bid, the quality of your ad and landing page, Ad Rank thresholds, how competitive the auction is, the context of the search, and the expected impact of your assets. With cost-per-click bidding you pay when someone clicks, and you're often charged less than your maximum bid.

This guide walks through the auction, Ad Rank, Quality Score, what you actually pay, and the campaign types a local business is most likely to use. For the full picture of how we run campaigns, start at our Google Ads hub.

What Google Ads Is

Google Ads is Google's advertising platform. It lets a business show ads on Google Search, YouTube, sites in the Google Display Network, and other Google properties. Search ads are the text ads that appear above and below the regular results when someone types a query like "garage door repair near me." The rest of the page, the unpaid listings, are the organic results, and Google keeps the two separate.

The model most people know is pay-per-click, or PPC. You don't pay for your ad to sit on a page. With CPC bidding, you pay when someone clicks. That's why a search campaign can work for a small business: you're paying for visits from people who were looking for what you sell.

How the Google Ads Auction Works

Google describes the process in its help article on the ad auction. In short, each time an ad is eligible to appear for a search, it goes through the auction, and the process repeats for every search. Here's the sequence:

1. Someone searches. Google finds every ad whose keywords match the search.
2. Ineligible ads drop out. Ads that target a different location, or that were disapproved under Google's policies, are ignored.
3. Ad Rank is calculated. Each remaining ad gets an Ad Rank. Ads that don't clear the minimum thresholds can't show.
4. Positions are set. The ad with the highest Ad Rank gets the top position, the next highest gets the second, and so on.

Because the auction runs fresh for every search, your position isn't fixed. The same ad can show first for one person, lower for another, and not at all for a third.

Keywords and Match Types

Keywords are the words and phrases you tell Google Ads you want to show for. Match types control how closely a search has to match a keyword before your ad can enter the auction. Google offers broad, phrase and exact match, and broad match is the default. We cover them in detail in broad match vs exact match keywords.

Ad Rank: What Decides Whether and Where Your Ad Shows

Ad Rank isn't one number you can look up in your account. Google calls it a set of values used to decide whether your ad is eligible to show and where it appears compared with other ads. It's calculated every time someone searches. According to Google's About Ad Rank page, it's based on six factors:

The practical point: the highest bid doesn't automatically win. Google says you can still win a higher position at a lower price with highly relevant keywords and ads. That's why so much of good campaign management is about relevance, not just bids.

Ad Quality at Auction Time

For the quality factor, Google uses auction-time measurements of expected clickthrough rate, ad relevance and landing page experience. These are worked out for each search, using the context of that search. That's different from the Quality Score you see in your account, which is explained next.

Quality Score: A Diagnostic, Not an Auction Input

Quality Score is a 1 to 10 rating shown at the keyword level. Google describes it as a diagnostic tool that gives you a sense of how your ad quality compares with other advertisers. Google is clear that Quality Score is not an input in the ad auction. It's a summary that points you to where your ads, keywords or landing pages could be better.

It has three components, each rated Above average, Average or Below average:

• Expected clickthrough rate: how likely your ad is to be clicked when it shows.
• Ad relevance: how closely your ad matches the intent behind the search.
• Landing page experience: how relevant and useful your landing page is to people who click.

Older articles, including an earlier version of this one, described Quality Score as a direct part of the auction formula. That's no longer how Google explains it. Read our full guide on Google Ads Quality Score for how to use it.

What You Actually Pay: CPC, Bids and Budgets

Two numbers get mixed up a lot. Your maximum CPC bid is the most you're willing to pay for a click. Your actual CPC is the final amount you're charged. Google says you're often charged less than your maximum bid, and with manual CPC bidding you're never charged more than it. Automated bid strategies and bid adjustments can change that.

Google also says higher quality ads can often lead to lower CPCs. So two businesses bidding on the same keyword can pay different amounts per click, depending on how relevant and useful their ads and pages are.

Daily Budgets

Each campaign has an average daily budget, the average amount you're comfortable spending each day. If you think in monthly terms, Google suggests dividing your monthly budget by 30.4 to get the daily figure. How much to spend depends on your market, your keywords and how many leads you need. Our guide on what to budget for Google Ads campaigns covers the factors.

Manual Bidding vs Smart Bidding

You can set bids yourself or let Google set them. Smart Bidding is Google's group of bid strategies that use Google AI to optimize for conversions. It includes Maximize conversions, Target CPA, Maximize conversion value and Target ROAS. Smart Bidding sets bids at auction time, using signals such as device, location and time of day. It only works well when conversion tracking is set up properly, because conversions are what it learns from.

Google Ads Campaign Types

The campaign type decides where your ads can appear and what they look like. These are the ones Google describes in its guide to choosing a campaign type:

For most service businesses, Search is the starting point because it reaches people who are already looking. Performance Max has its own trade-offs, which we cover in Performance Max for local businesses. Google also offers a separate ad product for local service providers, explained in our guide to home service ads.

What Makes a Google Ads Campaign Work

Knowing how the auction works points to where the effort should go. In our experience, these are the parts that matter most for a local business:

• Tight keyword groups. Group keywords by service so each ad can speak directly to what the person searched. Google itself recommends grouping keywords by theme to improve ad relevance.
• Negative keywords. Exclude searches you don't want to pay for, such as jobs, DIY or services you don't offer. Google lets you add them to campaigns or to an account-level list.
• A matching landing page. Send each ad to a page about that service, not your homepage. See why a dedicated landing page matters.
• Conversion tracking. Track calls, form fills and bookings so you know which keywords bring leads. Our guide on tracking ad performance for a service business explains the setup.
• Regular search term reviews. The search terms report shows the actual searches that triggered your ads. Reviewing it is how you find new keywords and new negatives.

Google Ads and SEO

Running ads doesn't change your organic rankings. Google states that investment in paid search has no impact on organic ranking. The two still work well side by side, because ads can cover searches where you don't rank yet while SEO builds over time. We explain how in how PPC and SEO work together. If you're weighing Google against social ads, see Google Ads vs Meta Ads for local service businesses.

Frequently Asked Questions

Does the highest bid always get the top ad position?

No. Position is decided by Ad Rank, which looks at your bid along with the quality of your ad and landing page, Ad Rank thresholds, auction competitiveness, the context of the search and the expected impact of your assets. Google says a highly relevant ad can win a higher position at a lower price.

Is Quality Score part of Ad Rank?

Not directly. Google says Quality Score is a diagnostic tool and not an input in the ad auction. The auction uses its own auction-time measurements of expected clickthrough rate, ad relevance and landing page experience. Quality Score summarizes those areas so you can see where to improve.

Do I pay my full bid for every click?

Usually not. Your maximum CPC bid is the most you're willing to pay, and Google says you're often charged less. With manual CPC bidding you're never charged more than your maximum bid, though automated bid strategies and bid adjustments can change that.

Will running Google Ads help my organic rankings?

No. Google states that investment in paid search has no impact on organic search ranking. Ads and SEO are still useful together, because ads can show for searches where you don't rank yet, and the search terms report can reveal keywords worth targeting with content.

Which Google Ads campaign type should a local business start with?

Most service businesses start with a Search campaign, because it reaches people who are already searching for the service. Other types, such as Performance Max, Display or Video, can be added once conversion tracking is working and you know which searches bring leads.

Get Help With Your Google Ads

Local Blitz has been in business since 2009, with offices in San Diego (Encinitas) and Indianapolis. We build and manage Google Ads campaigns for local businesses and report on the calls and leads they bring in. There are no cookie-cutter packages, plans are month-to-month, and your ad spend is paid directly to Google, separate from our management fee. See how we structure costs on our pricing page, or book a free strategy call. If Google Ads isn't the right fit for you, we'll tell you.