SEO vs PPC: Results From 1,500+ Agency Case Studies

Most SEO vs PPC articles are opinion. One side says organic traffic is free; the other says ads are faster. Very few show what each channel actually delivered for real clients.

This page compares them with data. It draws on 1,569 case studies from 64 marketing agencies in OpenServed's directory: 1,090 that list SEO, 818 that list PPC, and 339 that list both. For the head-to-head we use the 301 case studies that list SEO alone and the 206 that list PPC alone, because only those show one channel's results without the other mixed in.

Data as of October 2026. These are results agencies chose to publish, so they show what a successful campaign looks like, not what an average one does. If you cite a number, please cite the date.

SEO vs PPC at a glance

• SEO-only case studies report a median 98% increase in conversions or leads; PPC-only case studies report 74%.
• For leads alone, the two are level: 80% for SEO-only case studies and 78% for PPC-only ones.
• SEO-only case studies report a median 105% increase in revenue; PPC-only case studies report 80%.
• PPC case studies are far more likely to prove a business result. 82% of PPC-only case studies report revenue, leads or conversions, against 44% of SEO-only ones.
• Half of PPC-only case studies report a cut in acquisition cost, with a median cut of 38%. Only 1% of SEO-only case studies mention cost at all.
• 61% of SEO-only case studies report traffic and 44% report keyword rankings. For PPC-only case studies the figures are 9% and 1%.
• SEO clients are smaller. 64% of SEO-only clients are small businesses, against 40% of PPC-only clients.
• 31% of SEO case studies also list PPC, the most common pairing in the directory. Case studies that combine the two report a median 120% gain in conversions or leads.
• The data can't measure ROI or speed. Only 3 of the 1,569 case studies state a budget, and only 18 say how long the work took.

The short answer

Neither channel wins outright. SEO-only case studies report larger percentage gains, but they come from smaller clients starting from smaller bases, and fewer than half of them show a business result at all. PPC-only case studies report smaller percentage gains, but they almost always show conversions, and half show what those conversions cost. Which channel fits depends on your size, your industry and what you need to be able to measure. The last section of this page turns that into a choice.

What SEO and PPC case studies report

Before comparing results, look at what each channel's case studies choose to show. The two are sold and proven in different ways.

SEO case studies report traffic; PPC case studies report conversions and cost. Share of single-service case studies that include each result:

• Website traffic: 61% of SEO-only, 9% of PPC-only
• Keyword rankings: 44% of SEO-only, 1% of PPC-only
• Conversions or leads: 19% of SEO-only, 64% of PPC-only
• Revenue or sales: 25% of SEO-only, 26% of PPC-only
• Conversion rate: 3% of SEO-only, 31% of PPC-only
• Cost per acquisition or lead: 1% of SEO-only, 50% of PPC-only
• ROAS: 0% of SEO-only, 15% of PPC-only

PPC case studies are nearly twice as likely to show a business result. 82% of PPC-only case studies report revenue, leads or conversions. For SEO-only case studies it is 44%. The other 56% stop at traffic, rankings or impressions.

Revenue is the one result both channels report equally often. A revenue or sales stat appears in 25% of SEO-only case studies and 26% of PPC-only ones.

Cost is almost never part of an SEO case study. 72% of PPC-only case studies report an efficiency metric such as cost per acquisition, cost per click or ROAS. Only 3% of SEO-only case studies do.

SEO vs PPC results on shared metrics

Leads, conversions and revenue mean the same thing for both channels, so they can be compared directly. The figures below use single-service case studies only.

SEO-only case studies report larger gains in conversions and revenue; lead gains are level. Median reported gain, with the middle half in brackets:

• Conversions or leads: 98% for SEO only (56% to 400%, 44 case studies), 74% for PPC only (40% to 225%, 106 case studies)
• Leads: 80% for SEO only (53% to 368%, 26 case studies), 78% for PPC only (41% to 272%, 37 case studies)
• Conversions: 140% for SEO only (71% to 318%, 20 case studies), 74% for PPC only (38% to 224%, 71 case studies)
• Revenue: 105% for SEO only (55% to 260%, 67 case studies), 80% for PPC only (45% to 190%, 42 case studies)

Half of SEO-only case studies report that conversions or leads at least doubled. For PPC-only case studies it is 42%.

Conversion rate can't be compared. 54 PPC-only case studies report a conversion rate gain, with a median of 74%. Only 10 SEO-only case studies do, too few for a benchmark.

This is not proof that SEO outperforms PPC. Three things sit behind the gap:

• Smaller clients. 64% of SEO-only clients with a known size are small businesses, against 40% of PPC-only clients. Across the directory, small businesses report the largest gains in traffic and in conversions or leads.
• Smaller starting points. Organic leads and revenue often start near zero, so the same absolute gain is a bigger percentage.
• Different proof. PPC agencies often frame success as lower cost for the same volume, which doesn't show up as growth.

The order holds without the largest publisher on each side. Removing the agency that supplies the most data points to each group, the median revenue gain is 107% for SEO only and 77% for PPC only.

What each channel measures on its own

Some results exist for one channel only. They are shown side by side here, not as a contest. These figures come from all case studies that list each channel, and each links to its full breakdown.

SEO (SEO Statistics 2026):

• Organic traffic: median reported increase of 102% (462 case studies)
• Keyword rankings: median reported growth of 227% (173 case studies)

PPC (PPC Statistics 2026):

• Cost per acquisition or lead: median reported cut of 39% (197 case studies)
• ROAS: median reported increase of 82% (61 case studies)
• Click-through rate: median reported increase of 88% (68 case studies)
• Cost per click: median reported cut of 36% (45 case studies)

The single-service figures are close to these. SEO-only case studies report a median 110% increase in organic traffic (141 case studies), and PPC-only case studies a median 38% cut in acquisition cost (81 case studies).

SEO vs PPC by industry

No industry has enough single-service case studies for a clean comparison. This section uses every case study that lists each channel, bundles included, so a case study listing both counts on both sides. We merged industry labels into 13 groups (see methodology).

Every large industry uses SEO at least as often as PPC, but the gap varies. Share of each industry's case studies that list SEO and PPC:

• Industrial & Manufacturing: 60% SEO, 28% PPC
• Professional & B2B Services: 49% SEO, 21% PPC
• Retail & Ecommerce: 44% SEO, 28% PPC
• Home, Property & Local Services: 48% SEO, 38% PPC
• Financial Services: 31% SEO, 22% PPC
• Software & Technology: 37% SEO, 31% PPC
• Food & Beverage: 26% SEO, 22% PPC
• Healthcare & Wellness: 45% SEO, 43% PPC
• Fashion, Beauty & Jewelry: 38% SEO, 37% PPC
• Education & Nonprofit: 33% SEO, 33% PPC

Manufacturers and B2B firms lean hardest toward SEO. SEO appears more than twice as often as PPC in Industrial & Manufacturing and Professional & B2B Services case studies. In Healthcare, Fashion and Education the two are used about equally.

Lead gains by industry. Median reported gain in conversions or leads, for the five groups where both channels have at least 20 data points:

• Healthcare & Wellness: 195% for SEO (37 case studies), 93% for PPC (71)
• Industrial & Manufacturing: 136% for SEO (44), 134% for PPC (28)
• Retail & Ecommerce: 105% for SEO (21), 97% for PPC (29)
• Software & Technology: 104% for SEO (29), 69% for PPC (65)
• Home, Property & Local Services: 79% for SEO (27), 84% for PPC (32)

In three of the five, the channels are close. Industrial, retail and home services clients report similar lead gains from either channel. In healthcare and software, SEO case studies report clearly larger gains, while PPC has about twice as many data points.

Revenue gains for ecommerce are similar on both channels. The median reported revenue gain is 120% for SEO and 106% for PPC in Fashion, Beauty & Jewelry (61 and 60 case studies), and 107% for SEO and 92% for PPC in Retail & Ecommerce (90 and 76 case studies).

SEO vs PPC by client size

This section also uses every case study that lists each channel, bundles included. Client size is the client's employee count.

SEO skews toward small businesses; PPC is spread more evenly. Among SEO case studies with a known client size, 54% are small businesses (1 to 50 employees) and 10% are enterprises (more than 1,000). Among PPC case studies, 46% are small businesses and 15% are enterprises.

The smaller the client, the more SEO leads. SEO is listed in 55% of small-business case studies and PPC in 34%. For medium businesses it is 43% and 32%, and for large businesses 37% and 32%. For enterprises the two are level, at 18% and 19%.

SEO case studies report larger lead gains at every size we can measure. Median reported gain in conversions or leads, with the middle half in brackets:

• Small (1 to 50 employees): 131% for SEO (68% to 300%, 83 case studies), 107% for PPC (57% to 288%, 96 case studies)
• Medium (51 to 200): 93% for SEO (50% to 171%, 43 case studies), 86% for PPC (39% to 206%, 66 case studies)
• Large (201 to 1,000): 173% for SEO (51% to 362%, 35 case studies), 78% for PPC (40% to 160%, 55 case studies)

For enterprises, PPC case studies report a median 65% gain (47 case studies). SEO has only 18 enterprise data points, too few to report.

For small businesses, the two channels are close on revenue. The median reported revenue gain for small businesses is 105% for SEO (125 case studies) and 98% for PPC (96 case studies). For medium businesses it is 128% and 111% (32 case studies each).

What happens when SEO and PPC are combined

SEO and PPC is the most common pairing in the directory. 339 case studies list both. That is 31% of all SEO case studies and 41% of all PPC case studies.

Case studies that combine the two report the largest gains. Median reported gain, with the middle half in brackets:

• Conversions or leads: 120% together (65% to 300%, 94 case studies), 98% for SEO only, 74% for PPC only
• Revenue: 112% together (50% to 310%, 112 case studies), 105% for SEO only, 80% for PPC only

Organic traffic gains are smaller in combined case studies. The median reported increase in organic traffic is 86% where SEO and PPC are combined (130 case studies), against 110% for SEO alone (141 case studies). The cut in acquisition cost is slightly larger: 44% combined (32 case studies) against 38% for PPC alone (81 case studies).

Combined case studies sit between the two on proof. 69% report revenue, leads or conversions, against 44% of SEO-only and 82% of PPC-only case studies.

A combined case study can't say which channel produced the result, so read these as what agencies report when a client runs both, not as a sum of the two.

What the data can't tell you

It can't measure ROI. Only 3 of the 1,569 case studies state a budget. Without spend, there is no way to compare what each channel returned per dollar.

It can't measure speed. Only 18 case studies say how long the work took. A time period of any kind appears in the results of 21% of SEO-only case studies and 15% of PPC-only ones.

It only shows wins. Agencies publish their best work, and only 53 of the 1,569 case studies are Client-verified. Every number here is a published best case, not a typical outcome.

General context, not from this data: PPC can start producing clicks the day a campaign goes live, and stops when the spend stops. SEO usually takes months to build, and the traffic it earns doesn't end when a campaign does. That difference matters for the choice below, but our case studies can't put a number on it.

SEO or PPC: which should you choose?

The data doesn't pick a winner, but it does show where each channel has the stronger record.

• If you need to prove what a customer costs, PPC has the proof. Half of PPC-only case studies report a cut in acquisition cost. SEO case studies almost never mention cost.
• If you're a small business, SEO is the more common choice. SEO is listed in 55% of small-business case studies and PPC in 34%. Small businesses report a median lead gain of 131% from SEO and 107% from PPC.
• If you sell online, either can work. Both channels report revenue equally often, and reported revenue gains for retail and fashion clients are within 15 points of each other.
• If you're in manufacturing or B2B services, most of the evidence is for SEO. SEO appears more than twice as often as PPC in those industries.
• If you're in healthcare or software, compare both. SEO case studies report larger lead gains there, but PPC case studies report leads more often and are more likely to show cost.
• If you need results quickly, PPC is the usual answer. That comes from how the channels work, not from this data.
• If you can fund both, the combined record is the strongest. Case studies that list both report a median 120% gain in conversions or leads.

Whichever you choose, ask an agency for three things most case studies leave out: a business result, what it cost, and how long it took.

You can browse the case studies behind these numbers in OpenServed's SEO agency directory and PPC agency directory, and filter by industry, client size and location.

Methodology

• Source: all 1,569 case studies in OpenServed's directory that list SEO, PPC or both, as of October 5, 2026, from 64 agencies: 1,090 list SEO, 818 list PPC and 339 list both. Each links to the agency's own published case study.
• Single-service comparison: the head-to-head sections use the 301 case studies that list SEO as their only service and the 206 that list PPC as their only service. Bundled case studies can't show which channel produced a result.
• Industry and client size: these sections use every case study that lists each channel, bundles included, because the single-service groups are too small to split. A case study that lists both channels counts toward both.
• One set of rules for both channels: each case study carries the result stats the agency published, as free text. We assigned each stat to a metric by keyword matching, using the same rules for SEO and PPC case studies.
• Percentages only: medians use stats that state a percentage change. Plain counts, dollar figures and before-and-after pairs are left out.
• Direction: cost metrics count reductions; every other metric counts increases. Claimed cost reductions above 100% are excluded as impossible. Comparisons with a goal, target or industry average are left out.
• One data point per case study: if a case study has several stats for the same metric, we use the first one listed. "Conversions or leads" uses whichever comes first.
• Median and middle half: we report the median, not the average, because a handful of gains above 1,000% would distort an average. The middle half is the range from the 25th to the 75th percentile.
• Minimum sample: we compare the two channels on a metric or segment only when both have at least 20 data points.
• Channel-specific figures: the organic traffic, keyword, cost, ROAS and click-through figures are quoted from our SEO and PPC statistics pages, which exclude stats that name another channel.
• Industry groups: we merged industry labels into 13 groups. Client size uses employee count: small is 1 to 50, medium 51 to 200, large 201 to 1,000 and enterprise more than 1,000.
• Selection bias: agencies publish their wins, and the directory is not a random sample of the industry. Coalition Technologies supplies 25% of the SEO-only case studies and KlientBoost 26% of the PPC-only ones.
• Agency-reported: except for the 53 Client-verified case studies, results are as published by each agency and haven't been independently confirmed.

Cite this data: OpenServed, "SEO vs PPC: Results From 1,500+ Agency Case Studies", October 2026, https://openserved.com/blog/seo-vs-ppc