Pay per Click Advertising: How to Do PPC Marketing for a Store

A lot of stores lose their first month of PPC budget before the ads get a fair chance, because the expensive mistakes are set up front: no break-even number written down, a conversion count that logs every sale twice, and one budget split across five thin campaigns. Fix those three and the rest is detail. This is the version I wish somebody had handed me: the math first, the buttons later.

What is pay per click advertising?

Pay per click (PPC) advertising is advertising where you pay when somebody clicks your ad, not when it shows. On Google, that means Google Ads. You pick what to advertise, set a budget, and either set a bid or let Google bid toward a goal like sales. Every search runs an auction (how a click gets its price), and the winners show at the top of the page or in the Shopping results.

You will also hear it called paid search, search engine marketing, or still AdWords, which was Google Ads' old name. They all mean the same thing for a store: paying Google to show your products to people already searching for them.

How does Google Ads work?

Three parts work together. Your campaigns hold the ads and the budget. Your bidding strategy decides how much to offer in each auction. And the auction decides who shows. Most of the money in a store account runs through Smart Bidding now, which sets a fresh bid for every single search.

You pay mostly per click. Google also caps what you can spend: a campaign can spend up to two times its average daily budget on one day, and no more than 30.4 times it in a month. Our Google Ads cost guide has the full budget rules and what a click costs by industry.

The types of Google Ads campaigns

Google lists these campaign types:

• Search. Text ads on search results. Good for your brand name and specific questions. These are what people mean by Google search ads.
• Shopping. Product listings with a photo and price, built from your Merchant Center feed. What Google Shopping ads are.
• Performance Max. One campaign that reaches every channel, using your feed and assets. What Performance Max is.
• Display. Image ads on websites, in set sizes or responsive formats. How Google display ads work, and the frequency cap that stops one person seeing them too often.
• Video. Ads on YouTube.
• Demand Gen. Visual ads on YouTube, Discover, Gmail, Maps and the Display Network. What Demand Gen is.
• App. Ads that promote an app.

For an online store, the money is usually in Shopping or Performance Max, with a small Search campaign on the brand name. Display and Video are better at making people aware of you than at catching people ready to buy.

How to do PPC marketing

To do PPC marketing, work out what one sale is worth after your cost of goods, get conversion tracking right before you spend a cent, pick one channel and one campaign rather than five, set a testing budget you can lose, then read your search terms every week and cut what never sells. The number that decides all five is your break-even ROAS: 1 divided by your gross margin, so 2.5x at a 40% margin.

Start with what one sale is actually worth

Almost nobody does this first, and it is the number every later decision hangs off.

Say your average order is $80 and your gross margin is 40%. That means $32 of every order is yours before you pay for advertising. So $32 is your ceiling to acquire one customer. Spend $33 and you paid to lose money.

Turn that into the number platforms use. Break-even ROAS is 1 divided by your margin. At 40% margin, that is 2.5x. So:

• 2.4x is a loss
• 2.5x is exactly nothing
• 3.0x is a real profit

Write your number on a sticky note. Every "is this working" question you will ever ask has that number as its answer. It is also decision one in our PPC strategy guide, which walks through the six that follow it.

A 4x ROAS on a 20% margin product makes you less money than 2.6x on a 50% margin one.

- The number that ends most arguments

What you are actually buying in the auction

People assume the highest bid wins. It does not, and knowing why saves you a lot of money.

Google ranks ads on something called Ad Rank, and it says the score is "calculated based on many factors, including your bid amount, the quality of your ads and landing page, the Ad Rank thresholds, the competitiveness of an auction, the context of the person's search (for example, the person's location, device, time of search, the nature of the search terms, the other ads and search results that show on the page, and other user signals and attributes), and the expected impact of assets and other ad formats."

And it happens twice per search: "In each auction, your Ad Rank is calculated first to determine whether your ad is eligible to show, and a second time to determine where your ad is ranked relative to other eligible ads."

We break down what that means for your price per click in CPC for Google Ads.

Two things follow. Your bid is one factor on a long list, so a better page and a better ad can beat a bigger wallet. Google says that part outright: "even if your competition has higher bids than yours, you can still win a higher position at a lower price by using highly relevant keywords and ads." And there is no fixed position you own. Every single search runs the whole thing again, which is why your average position wobbles for no reason you can see.

Pick one campaign, not five

New advertisers build five campaigns because the interface offers five options. Then the budget splits five ways, nothing gets enough data to learn from, and every campaign looks mediocre.

For an online store, start with one campaign built off your product feed, either Shopping or Performance Max. Google builds those ads from your product data, so your product titles are doing the work that keywords do elsewhere. Add a small Search campaign on your own brand name in exact match if people already look you up.

You can always add later. You cannot un-split data you already spread too thin. The full build order for a store, from feed to bidding on profit, is in Google Ads for ecommerce.

The budget question, with real numbers

Two rules from Google explain most budget panic before it starts.

Your campaign can spend up to two times your average daily budget on any one day. Across the month it is capped at 30.4 times the daily figure, since 30.4 is 365 divided by 12. A $50 a day budget spending $100 on a Wednesday is documented behavior, not an overspend, and it usually means Google found a good day.

The floor that matters is clicks, not dollars. You need enough clicks that one lucky sale cannot make a bad campaign look brilliant, and one unlucky stretch cannot kill a good one. Work the number out from your own cost per click: the clicks you need in order to learn, times what a click costs you. If you cannot fund that learning window, do not start yet.

How to tell if it is working

Three checks, in this order.

First, does one sale count once? Compare Google's conversions against real orders in your store for the same period. If Google counts more conversions than your store has orders, something is double counting, and every number below it is wrong.

Second, what are people actually typing? The search terms report shows the real searches your ads showed for. Google distinguishes them clearly: "A search term is a word or set of words a person enters when searching on Google or one of our Search Network sites." A keyword is what you added. You pay for the search term. Sort it by cost and look for spend with no sales.

Be aware you never see the full list. Google says terms without enough query activity are left out "in order to keep with our standards on data privacy". Your waste is always a bit bigger than the report shows, which is an argument for looking weekly.

Third, are you above your break-even number, per product, over a meaningful learning window? Not per day. Not blended into a single account figure that hides your losers.

The weekly routine that keeps it alive

One short pass a week beats one big rebuild a quarter.

• Read the search terms with spend and no sales, add negatives
• Check Merchant Center for disapproved products
• Look at the five products with the most spend and check each one against your break-even
• Check pacing against your monthly budget
• Change one thing, not six, so you know what caused what

The one-thing-at-a-time rule is the part people skip. Change six settings on Monday and by Friday you have no idea which one helped. The Google Ads optimization checklist walks through the same loop in more detail, in the order that matters.

When PPC marketing is the wrong call

Sometimes PPC is the wrong tool.

Start with your margin, because thin margins make the math brutal. At a 20% gross margin your break-even ROAS is 5x, so every dollar of ads has to bring back five just to stand still. If your own sum lands on a number your category cannot plausibly clear, paid search is the wrong tool.

If nobody searches for what you sell, search cannot help you. Paid search harvests demand that already exists. It does not create it. A brand new product category with zero search volume is a Meta or TikTok problem first, and those platforms are better at making people want something they were not looking for. Come back to Google once people start typing your product name.

And if you only have a small testing budget, put it into your product photos and your product pages instead. Those improve every channel you ever run, forever.

Who should run it

Once the account is real, PPC marketing splits into two jobs, and they suit different people.

If you want to learn to do both jobs yourself, start with our Google Ads training guide.

The thinking job is offers, pricing, creative, which market to enter. That is a human, either you or an agency, and it is worth paying for when you need judgment rather than hours.

The grinding job is the weekly list above, done properly, every week, forever. Humans are bad at that specific thing because it is dull. Software is good at it for the same reason. Our ranking of PPC tools covers what automated PPC actually means today, and which tool does which job.

Scaley is our answer to the grinding half, and I built it, so weigh that. Scaley Suite reads your Google Ads account and Merchant Center every day, tags every product by margin and speed of sale, flags wasteful search terms and loss-making products with the evidence next to it, and changes nothing in your account until you approve each change. I also run ZenoX Media, a Google Ads agency, so I have a foot in both camps and you should read the paragraph above knowing that.

Scaley Suite is the tier that writes to the account, and every write waits for your yes. Its price moves with your spend, unlike a flat agency retainer. The pricing page has the current numbers. If the weekly list is still easy to handle yourself, keep doing it and keep the fee.

See current Suite pricing, or read how the Google Ads AI works and what it does day to day before you connect anything.

Where these facts come from

Everything above that Google says is quoted from Google's own help pages, checked on the date next to each one:

• Ad Rank: Definition - the factors behind Ad Rank, the line about beating higher bids with better ads, and Ad Rank being calculated twice in every auction. Checked 2026-08-20.
• About average daily budgets - the two times daily spending limit, and the 30.4 times monthly cap. Checked 2026-08-20.
• About search terms - the definition of a search term, and terms being left out to keep with Google's standards on data privacy. Checked 2026-08-20.
• Choose the right campaign type - Performance Max, Search, Display, Video, App and Shopping, each with Google's one-line description. Checked 2026-10-08.
• About Demand Gen campaigns - the surfaces Demand Gen runs on. Checked 2026-10-08.

The margin and break-even math is arithmetic you can redo with your own numbers.