It’s the question that kicks off almost every meeting: “Which makes more sense for me, SEO or Google Ads?” It’s almost always answered wrong, because people compare two things that can’t be compared: the price of a click versus a monthly retainer. The only apples-to-apples metric is what each customer you win actually costs. That’s the math we do here—with a formula, an example, and data from our own site.
The only metric that matters for comparison
Forget CPC and the SEO package price for a moment. What your business pays is the cost per customer: everything you invested in the channel, divided by the customers you closed thanks to it.
In Google Ads, the math looks like this:
Cost per customer = cost per click ÷ page conversion rate ÷ sales close rate.
In SEO, like this:
Cost per customer = monthly investment ÷ customers who came from organic search that month.
Sounds obvious, but most businesses that come to us don’t have any of the three inputs in the first formula measured. Without them, “Ads is expensive” or “SEO doesn’t work” are opinions, not diagnoses.
Google Ads in Cancún: a range-based example
Let’s take a service business in Cancún competing for local searches. With the caveat that every industry and season shifts the numbers, a reasonable scenario looks like this:
- Cost per click: between 15 and 45 pesos.
- Page conversion rate (out of 100 visits, how many write or call): between 3% and 8%.
- Close rate (out of 100 contacts, how many buy): between 10% and 25%.
Within those ranges, a customer can cost you from about 750 pesos —cheap click, strong page, strong salesperson— up to about 15.000 pesos —expensive click, weak page, slow follow-up—. Twenty times apart with the same budget and the same market.
The takeaway isn’t the middle number. It’s that two of the three levers aren’t on Google: your page and how you handle the lead are yours. That’s why two neighboring businesses, bidding on the same keyword, end up paying per customer amounts that have nothing in common.
Ads has clear pros: it works from day one, it’s measurable to the penny, and you can switch it off anytime. The con is just as clear: the day you stop paying, you disappear. Nothing you invest sticks.
SEO in Cancún: what our own numbers say
For SEO, we won’t use a hypothetical. We’ll use what Search Console gave graphemics.net in the last 180 days, from March 30 to September 26, 2026:
- 94 distinct searches including “Cancún” showed us in Google, with 7.002 impressions in total.
- Just those combining SEO or posicionamiento with Cancún are 27 searches and 3.892 impressions, at an average position of 26,7. Page three.
- The biggest, “seo cancun”, showed us 584 times at position 14,1: one push away from page one.
- Clicks from that whole group: zero.
That zero is the most important data point here—and not because it’s bad. It shows how SEO works: the demand is already there, measured by Google, and impressions cost nothing. What’s missing is moving up. And nobody clicks from page three.
One nuance often overlooked: Google counts an impression only if the result was actually shown. On page three that happens when someone bothered to scroll that far. The real demand for those searches is higher than the 3.892 impressions we see.
What happens when you put them side by side
In the same period and on the same site, searches that mix Google Ads or publicidad with Cancún gave us 26 impressions. “google ads cancún” alone, 13. Against almost 3.900 from the SEO group.
It’s not a sample of the entire market: it’s what Google shows us, based on what we’ve published. But it does prove one concrete thing: people in Cancún look for someone to solve posicionamiento far more than they look for someone to manage their ads. Organic demand exists and is free per click. The question is how much it costs to reach it.
When each one is cheaper
With both formulas in front of you, the answer stops being ideological:
- Google Ads is cheaper at the start—always. During the three to six months it takes a new service page to settle, SEO costs money and brings no one. In that stretch, SEO’s cost per customer is infinite, and Ads has a number.
- SEO becomes cheaper once it ranks. Once your page is on page one for queries with demand, the monthly fee is spread across more customers each month, and the cost per click is zero. Over time, SEO’s cost per customer goes down; Ads, at best, stays flat.
- Ads is cheaper for short-lived plays. A high-season promotion, an event, a fixed-date launch: there isn’t time to rank anything, and it’s not worth trying.
- SEO is cheaper for year-round searches. If your service is searched the same in February as in October, paying for every click of every month of every year is the expensive option.
How we do it
We don’t pick one. We’ve been managing Google Ads for America Car Rental for over ten years —nineteen cities and two hundred campaigns— and in that time we learned Ads and SEO don’t compete: they feed each other. Our sequence:
- Ads first, with a lean budget and full tracking. In the first months, Ads brings customers and, more importantly, tells us which searches end in sales and which just bring tire-kickers.
- SEO on the searches that have already proven they sell. You don’t rank a keyword on intuition: you rank the one Ads has already validated with money.
- Search Console as the map. Anything already getting impressions between positions 11 and 30 is confirmed demand halfway there. It’s the cheapest to lift.
- Dial Ads down where organic has arrived. When a query is in the top organic results, reduce the ad on that same term and move that budget to the next one.
The three numbers you need to know before deciding
If you can’t answer these three today, you’re not ready to choose between SEO and Ads—and anyone selling you either without asking them is selling blind:
- Out of 100 visits to your site, how many write or call?
- Out of 100 contacts, how many end up buying?
- On average, what’s the value of a new customer?
With those three, you can run the comparison in a spreadsheet in an afternoon. Without them, any decision is a coin flip.
If you want the math done for your business
We can run it using your own data: which Cancún searches already give you impressions in Search Console, at what position, and what each customer would cost you via Ads and via SEO with your real rates. Write to us and we’ll send it with the numbers in front of you, so you decide—not the agency.
The impression, position and click figures come from Google Search Console for graphemics.net, period from March 30 to September 26, 2026, checked on September 28, 2026. The cost per click, conversion and close-rate ranges in the Google Ads example are indicative: they vary by sector, season and competition, and don’t replace measurement in each account.
Versión en español: SEO o Google Ads en Cancún: cuál sale más barato por cliente
