In short
- PPC buys clicks immediately and stops as soon as the budget stops. SEO takes time but produces traffic that accumulates.
- CPC gives every query a market price: it lets you put a figure on what your organic traffic would cost if you had to buy it.
- High-CPC transactional queries, the ones behind your categories and facets, are where SEO saves the most.
- The best setup uses PPC data (the search terms report) to choose which pages to optimize for SEO.
"Should you invest in SEO or in Google Ads?" is one of the first questions an e-commerce owner asks. It is the wrong way to frame it. SEO and PPC are not two competing options, they are two ways of buying the same traffic: one is paid for in clicks, the other in time and work. The real question is where each one is most profitable.
What really sets them apart
| PPC (Google Ads, Shopping) | SEO (organic search) | |
|---|---|---|
| Time to results | Immediate | Several weeks to several months |
| Cost | Every click is paid for | The work is paid for once, clicks are free |
| Stopping | Traffic stops with the budget | Traffic persists and accumulates |
| Control | Total: queries, copy, bids, budget | Partial: Google decides the ranking |
| Measurement | Precise, query by query | More indirect |
| Competition | Played out on budget | Played out on page quality |
PPC is unbeatable for launching a product, testing an offer or covering a seasonal peak. SEO is unbeatable over time: a well-ranked category brings in traffic every month, with no marginal cost.
CPC, the market price of your traffic
Cost per click is not just a line of spending. It is a market price: the amount advertisers, who measure their sales down to the cent, are willing to pay for a visit on a given query.
This makes it possible to put a figure on the value of your organic traffic. Take a few French queries:
| Query | Monthly volume | Average CPC |
|---|---|---|
| cat food for neutered cats | 9,900 | $2.08 |
| robot lawn mower | 90,500 | $0.97 |
| 160x200 fitted sheet | 14,800 | $0.83 |
| cordless stick vacuum | 22,200 | $0.52 |
| how to fold a fitted sheet | 1,600 | $0.11 |
Google France, October 2026. Source: DataForSEO.
If your "160x200 fitted sheet" category receives 1,000 organic visits per month on queries of this type, getting the same traffic through ads would cost in the region of $800 per month, every month. That is what your SEO saves you. The same calculation on an article that attracts 1,000 readers on "how to fold a fitted sheet" gives around $110.
This calculation is an estimate, but it highlights an essential point: SEO saves the most on high-CPC transactional queries, that is, those behind your categories and facets. It is also the conclusion of our analysis of e-commerce SEO traffic.
Making the two work together
Using PPC to choose what to optimize for SEO
Google Ads' search terms report is a goldmine for SEO. It shows, query by query, which ones generate sales and at what cost. Queries that convert well and cost a lot are priority targets for SEO: every position gained in organic can reduce your advertising spend.
This report often reveals long-tail queries that your SEO tools underestimate: "extra deep 160x200 fitted sheet", "grain-free food for neutered cats". These are exactly the facets to create or optimize.
Using SEO to reduce ad spend
When a category durably reaches the top organic positions on a query, you can test lowering bids on that query and measure the effect on total sales. On some queries, the ad and the organic result cannibalize each other; on others, appearing twice increases the overall click-through rate. Only testing will tell.
Using PPC to test title tags
Ad copy that achieves an excellent click-through rate gives you ideas for the title tag and meta description of the corresponding category. PPC lets you test in a few days an argument that SEO would take weeks to validate.
What about the AI Overview?
The AI Overview changes the results page, but very unevenly depending on intent. In our study of 599 French queries, it appears on 70% of informational queries but 9% of transactional ones, where Google mostly displays product modules. Semrush also observes that results pages combining ads and AI Overviews grew sharply in 2025 in the United States.
For an e-commerce owner, this reinforces the logic described above: SEO and PPC converge on the same transactional queries, the ones that sell.
In summary
- PPC for the immediate, for tests and for data.
- SEO for the long run, on the queries PPC taught you to value.
- Categories and facets at the center of both, because they are the pages that receive purchase traffic.
Optimizing the tags and copy of hundreds of categories and facets is the bottleneck of this setup. It is the work unblind automates, drawing on the queries observed in Google Search Console and on DataForSEO ranking estimates to choose each page's main query.
Frequently asked questions
What is the difference between SEO and PPC?
SEO (search engine optimization) means optimizing your site to appear in the organic results, which are free per click. PPC (pay-per-click advertising) means buying ads, paid for on every click, that appear above or next to the organic results, notably through Google Ads and Google Shopping.
Do you have to choose between SEO and PPC?
No. PPC brings immediate sales and precise data on the queries that convert. SEO builds durable traffic on those same queries. High-performing sites combine the two and pass learnings from one to the other.
How much is my SEO traffic worth?
A simple method is to multiply the organic clicks received on each query by its average CPC. That gives the amount you would have to spend on ads to get the same traffic. It is an estimate, but it makes it possible to compare the value of pages with one another.