How to Do PPC Marketing for an Online Store

You pay for every visitor instead of waiting for one. That is the whole idea behind PPC marketing, and the first invoice is where most people find out how much detail is hiding inside it. This is the version I wish somebody had handed me: the math first, the buttons later.

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 budget you can lose for 30 days, then read your search terms every week and cut what never sells. That is the whole loop. Nearly everything sold as advanced PPC is one of those five things done with better data. The number that decides all five is your break-even ROAS: 1 divided by your gross margin, so 2.5x at a 40% margin.

If you have not built the account yet, our step by step Google Ads setup guide covers the billing, the tracking and the first campaign. This post is about how to run it once it exists.

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.

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."

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.

That is it for month one. You can always add. You cannot un-split data you already spread too thin.

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 euros. You want somewhere around 300 to 500 clicks a month before the numbers mean anything. Under that, one lucky sale makes a bad campaign look brilliant. At a €1 cost per click that is €300 to €500 a month. In an expensive category it is more, and if you cannot fund that, do not start yet. Spending €100 a month on paid search is a slow way to learn nothing.

That one is written for dropshipping accounts, but the click floor above is the same wherever you sell. What decides whether you can learn anything is clicks a month, not the product.

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 seven days. If Google is more than 5% higher, 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 30 days? Not per day. Not blended into a single account figure that hides your losers.

The weekly routine that keeps it alive

Twenty minutes, once a week, beats a four-hour rebuild once 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. How to optimize a PPC campaign walks through the same loop in more detail, and what PPC optimization actually covers is the wider map.

When PPC marketing is the wrong call

Worth saying plainly, because plenty of people will happily take your money either way.

If your gross margin is under about 20%, paid search rarely works. There is not enough left in the order to pay for a click and still leave you something.

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 genuinely 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 have under €1,000 total to spend, 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.

The thinking job is offers, pricing, creative, which market to enter. That is a human, either you or an agency. A good ecom agency usually costs €3,000 to €8,000 a month, and it is worth it 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. Automated PPC, in plain words covers what that actually means today.

Scaley is our answer to the grinding half, and I built it, so weigh that. It watches your Google Ads account and your Merchant Center feed 24/7, tags every product by margin and speed of sale, flags every wasteful search term and loss-making product with the evidence next to it, and writes nothing to your account until you approve it. 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.

It costs 4% of the ad spend it manages, billed in dollars, with a $199 a month floor, so a $3,000 a month account pays $199. That is a different shape from the agency retainer above: theirs is flat whatever you spend, this one moves with your spend. Full pricing here. Below roughly €5,000 a month in spend, honestly, do it yourself with the weekly list and keep the fee.

Start the free trial and the first pass is read-only, so nothing changes while it looks. 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 2026-08-20:

• 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.
• About average daily budgets - the two times daily spending limit, and the 30.4 times monthly cap.
• About search terms - the definition of a search term, and terms being left out to keep with Google's standards on data privacy.

The margin and break-even math is arithmetic you can redo with your own numbers. The agency and software costs come from what the team at ZenoX Media quotes and what Scaley charges.