The short answer: PPC buys you traffic today and stops the moment you stop paying. SEO takes 3 to 6 months to build momentum, then keeps producing at a falling cost per lead. On most budgets the winning move isn’t choosing, it’s sequencing: PPC for revenue now, SEO for a cost per conversion that drops every quarter. Here’s the full math.
SEO vs PPC at a Glance
| SEO | PPC | |
|---|---|---|
| Time to results | 3-6 months to gain momentum | Immediate |
| What you pay for | Content, optimization, authority | Every single click |
| When you stop paying | Rankings keep working | Traffic stops same day |
| Typical conversion rate | ~2.4% from organic traffic | ~1.3% from paid clicks |
| Cost trend over time | Falls as rankings improve | Flat or rising with competition |
| Best for | Long-term growth, compounding returns | Launches, promos, time-sensitive offers |
What Each One Costs
SEO usually asks for more up front: a technical foundation, content, and on-page work before rankings move. After that, ongoing costs are predictable and the cost per visitor falls as positions improve. PPC flips it: setup is fast and cheap, but you fund every click forever, and competitive industries push those clicks up over time.
The costs people forget to count: landing pages and creative for PPC, content production for SEO, and tracking for both. If you can’t see which channel produced which lead, you can’t manage either budget.
Cost Per Conversion: The Number That Actually Decides This
Clicks are vanity. Cost per conversion is what your budget feels. Here’s an illustrative month with a $2,000 spend in each channel, using the conversion rates above:
| Scenario ($2,000/mo) | Traffic | Conversion rate | Leads | Cost per conversion |
|---|---|---|---|---|
| PPC at $2.50 per click | 800 clicks | 1.3% | ~10 | ~$200 |
| SEO, month 3 (early rankings) | ~500 visits | 2.4% | ~12 | ~$167 |
| SEO, month 9 (established rankings) | ~2,000 visits | 2.4% | ~48 | ~$42 |
The pattern holds across industries even when the exact numbers move: PPC’s cost per conversion stays roughly flat, while SEO’s falls as rankings compound. That’s why the smartest budgets use PPC to buy the first two quarters of leads and SEO to make quarters three onward progressively cheaper.
Time to Results and What History Says About Risk
PPC delivers from day one and stays steady as long as you feed it. SEO takes 3 to 6 months, and it carries algorithm risk: the 2023 Google Helpful Content Update cost some sites up to 90% of their organic traffic overnight while PPC campaigns sailed through unchanged. The lesson isn’t “avoid SEO.” It’s don’t build your only pipeline on a channel you don’t control, in either direction.
What to Run at Each Budget Level
Under $5,000/month
Lean SEO-first. A small PPC budget in a competitive industry burns out quickly without lasting results, while a local service business putting $3,000 a month into SEO can reach positive ROI as local rankings land. Keep a small PPC reserve for offers that can’t wait.
$5,000 to $20,000/month
Run both. This is the range where the combination outperforms either channel alone: PPC covers the demand you need this month while SEO builds the asset. One SaaS example from our research: scaling SEO spend in this range grew traffic 150%, against 70% from the equivalent PPC push in a saturated market.
Over $20,000/month
Balance and dominate. With organic converting at roughly double the rate of paid, large budgets use PPC for time-sensitive campaigns and SEO for authority, and aim to hold both the ad slot and the organic ranking on money keywords.
How SEO and PPC Work Better Together
- Test keywords with PPC first. A two-week ad test tells you which terms convert before you commit months of SEO to them.
- Retarget organic visitors. PPC re-engages people who found you through search and didn’t convert the first time.
- Own the whole results page. Ranking organically and running an ad on the same term pushes competitors below the fold on your most valuable searches.
- Keep organic as your insurance. When you pause ads, the rankings you built keep working at a lower cost.
Frequently Asked Questions
Is SEO or PPC cheaper?
PPC is cheaper to start; SEO is cheaper to sustain. By month 9-12, an established SEO program typically produces leads at a fraction of PPC’s cost per conversion, but you pay for the ramp-up months first.
What’s a typical cost per conversion for SEO vs PPC?
It varies by industry, but the mechanics are constant: organic traffic converts around 2.4% versus roughly 1.3% for paid clicks, and SEO’s cost per conversion falls as rankings improve while PPC’s stays tied to click prices.
How long before SEO pays for itself?
Expect 3 to 6 months before momentum and roughly 6 to 12 months before SEO’s cost per lead beats PPC’s in most industries. Local niches often get there faster.
Should a small business start with SEO or PPC?
If you need revenue this month, start PPC with a tight budget while SEO builds underneath. If you can invest for two quarters, SEO-first usually wins on total cost per customer.
Get the Right Mix for Your Budget
We run both sides of this equation every day: SEO plans from $1,500/mo with AI SEO and digital PR included, and Google Ads management from $1,500/mo. Or book a free strategy call and we’ll map the split for your budget, or start with a free SEO audit to see where organic can take you.
