The essentials
- The short answer: Google Ads first if you need customers within three months and have a media budget; SEO first if your market has high CPCs and you can wait six to twelve months.
- Split observed in 2026: the SMEs that succeed start at 70/30 in favour of Google Ads and shift towards 40/60 in 18 to 24 months.
- Decisive criterion: the cost of a click on your queries: above €4 to €5, every organic position gained is worth several thousand euros a year.
- Common mistake: stopping Google Ads as soon as SEO delivers, when the two together capture more than either alone.
The question is not which one is "better": SEA and SEO do not do the same job and are not paid for in the same way. The question is one of order and split, for a given company with a limited budget. This article gives a decision grid; the detailed comparison of the two levers is in SEA vs SEO: differences and how they complement each other.
The four questions that decide
- How soon do you need customers? Less than three months: Google Ads. SEO produces nothing measurable before four to six months on a recent site, and often twelve.
- How much does a click on your queries cost? Check in the Keyword Planner. Below €1, Google Ads is cheap and SEO is less urgent; above €4, every organic position is worth a lot and SEO becomes a high-return investment.
- Can your site convert? Without a page that turns a visit into an enquiry, neither one pays off. The first week's budget goes to that page.
- Do you have content or expertise to show? SEO requires pages; if nobody can write them or have them written, it will remain theoretical.
The decision grid
| Situation | Priority | Starting split | Reason |
|---|---|---|---|
| Business launch, new site | Google Ads | 80% SEA, 20% SEO (technical foundations and main pages) | SEO on a site with no history takes 6 to 12 months; you need customers before then |
| Local services (tradesperson, healthcare, consulting) | Both, starting with the Google listing | 50% SEA, 50% local SEO | The local pack captures a large share of "near me" searches for free |
| E-commerce with a catalogue | Google Ads (Shopping, Performance Max) | 70% SEA, 30% SEO | Shopping product listings convert; SEO works on the categories |
| B2B with a long cycle and high CPC (€5 to €15) | SEO and content | 40% SEA (brand and high-intent queries), 60% SEO | Bought clicks cost too much to cover the whole journey |
| Established site, good organic traffic, growth to accelerate | Google Ads on what SEO does not cover | 60% SEA, 40% SEO | SEO has reached a plateau; SEA captures the competitive queries |
| Seasonal or promotional market | Google Ads in season, SEO out of season | Variable | SEA is steered day by day; SEO prepares the following season |
The 24-month shift timeline
At the SMEs that combine the two successfully, the split evolves along a recurring pattern:
| Period | Google Ads | SEO | What happens |
|---|---|---|---|
| Months 1 to 3 | 70 to 80% | 20 to 30% | SEA brings the first customers and reveals the queries that convert; SEO fixes the technical side and creates the main pages |
| Months 4 to 9 | 60 to 70% | 30 to 40% | SEA data guides the SEO content; first organic positions on the long tail |
| Months 10 to 18 | 50 % | 50 % | Organic traffic covers the brand queries and part of the generic ones; SEA concentrates on the competitive queries and the conversion campaigns |
| Months 18 to 24 | 40 % | 60 % | The blended cost of acquisition falls by 25 to 40% compared with month 3; SEA stays active on what remains profitable |
This pattern assumes a stable total budget. Shifting does not mean cutting Google Ads but reallocating what it no longer brings in (the queries already covered in organic positions 1 to 3) towards what it still brings in.
What each brings to the other
- From SEA to SEO: the search terms report shows within a few weeks which queries convert, with their volume and their cost; that is the best basis for choosing which SEO pages to create. Ad tests also reveal which headlines get clicks, reusable in the title tag.
- From SEO to SEA: a page built well for SEO makes a good landing page and improves the Quality Score, and therefore the CPC. Organic traffic feeds the remarketing lists.
- Together: an ad and an organic result on the same query capture more clicks than either alone; tests that pause SEA on brand queries show a net loss of 10 to 25% of clicks, not a full transfer to organic.
How to measure the trade-off
The only metric comparable between the two levers is the full cost per conversion: media budget plus fees plus internal time, divided by the conversions attributed. For SEO, count the conversions from organic traffic in GA4 over a rolling twelve months, against the cumulative investment; for SEA, the monthly cost per conversion. Bringing them together in a single dashboard avoids biased comparisons; the method is described in connecting GA4 and Search Console in a dashboard. One useful intermediate metric: the share of conversions coming from queries where you appear both as an ad and in an organic position; if it exceeds 30%, lower the bid on those queries and observe. The overall calculation is that of Marketing ROI.
How GreenRed helps
Rather than juggling several tools, GreenRed's return on investment module brings these metrics together in a single dashboard, compares them over time and tells you which actions come first. You can try it free, with no card, from the Pricing.
Frequently asked questions
Can you do SEO without a Google Ads budget?
Yes, but with a delay of six to twelve months before measurable results on a recent site, and without the data on the queries that convert. A small Google Ads campaign of €300 to €500 per month for two months provides that data and avoids writing pages on queries that bring in nothing.
Should you cut Google Ads when SEO is working?
Not entirely. Lower the bids on the queries where you hold the top three organic positions, and keep the budget on the competitive queries, the remarketing campaigns and the commercial periods. Tests show that stopping ads on well-ranked queries loses 10 to 25% of clicks.
What minimum budget do you need to run both in parallel?
For an SME, a total of €1,500 to €2,500 per month allows you to combine a Search campaign of €800 to €1,500 and SEO support of €600 to €1,000 (technical, content, tracking). Below that, concentrate on a single lever for six months rather than spreading thin.
Is SEO really free?
The click is free, the visibility is not. SEO costs writing time, technical fixes, link building and monitoring, that is €500 to €3,000 per month for an SME depending on ambition. Its advantage is that the cost does not grow with the number of clicks, unlike Google Ads.