In Healthcare, Ten Employers Post Half the Jobs. In Marketing, an Eighth.
Based on 231,147+ analyzed job listings · Updated 2026-07-21
Job search advice treats every market as if it has the same shape. It does not. We measured how concentrated hiring is across 27,544 employers, and the answer varies by nearly four times depending on the industry. In healthcare, the ten largest employers account for 49.3% of every active listing, so researching ten organisations covers half the market. In marketing, the same ten cover 12.4%, and a strategy built on targeting them would miss almost nine listings in ten. The same effort, allocated correctly or incorrectly, entirely because of which field you are in.
49.3%
Healthcare, top 10 employers
Of all active healthcare listings, led by Kaiser Permanente
12.4%
Marketing, top 10 employers
The most fragmented market we measured
52.2%
Employers posting in one function only
Of 27,544 employers with active listings
79.2%
Listings held by broad employers
The 13.7% of employers hiring across five or more functions
How concentrated hiring is, by industry
| Industry | Listings | Top 10 employers hold | Largest employer |
|---|---|---|---|
| Healthcare | 12,031 | 49.3% | Kaiser Permanente |
| Product | 5,653 | 38.2% | Amazon |
| HR / recruiting | 31,628 | 33.1% | Amazon |
| Operations | 37,131 | 30.9% | Amazon |
| Finance | 30,046 | 29.9% | JPMorgan Chase |
| Data / analytics | 24,895 | 25.3% | Amazon |
| Engineering | 75,822 | 22.5% | Amazon |
| Design | 3,834 | 15.7% | Amazon |
| Sales | 19,730 | 13.5% | Amazon |
| Marketing | 18,142 | 12.4% | Amazon |
Share of active listings in each industry posted by that industry's ten largest employers. Employer names are normalised for case and job-board aggregator accounts are excluded, so the counts reflect employers rather than the sites we ingest from.
Source: Seeker job corpus, 231,147 active job postings, snapshot 2026-07-21. seekerscore.com/insights/employer-concentration-2026
The same search, two opposite strategies
Healthcare is the most concentrated market in the corpus. Ten employers post 49.3% of listings, and Kaiser Permanente alone leads it. If you are a nurse or a pharmacist, deep research on ten organisations, their hiring cycles, their internal systems and their credential requirements covers half of everything available. Marketing is the opposite. Its ten largest employers post 12.4%, so the equivalent research covers roughly an eighth of the market and the remaining 87.6% sits with employers you have never heard of. Sales at 13.5% and design at 15.7% behave the same way. In those fields, breadth of search beats depth of research, and the reverse is true in healthcare.
Amazon is the largest employer in seven of eleven industries
One employer tops engineering, operations, HR, data and analytics, product, sales, marketing and design. That is not a statement about Amazon being a good or bad employer, it is a structural fact about who publishes job listings at scale. It also creates a trap in interpretation: a concentrated market is not automatically one where a few household names dominate. Healthcare is concentrated around hospital systems and pharmacy chains, most of which are regional. Finance concentrates around JPMorgan Chase. The identity of the top employer says as much about the industry as the concentration figure does.
Half of employers hire for one thing, and they are not where the jobs are
Of 27,544 employers with active listings, 52.2% post in a single functional domain. Only 13.7% hire across five or more. But those broad employers hold 79.2% of all listings. Both halves of that matter and they point in different directions. If you want to change function without changing employer, the majority of the market structurally cannot offer it, and the ones that can are nameable: Amazon spans 20 domains, Apple 19, Johnson and Johnson 19, Google 18, JPMorgan Chase 17. If you simply want volume of opportunity, you are already applying mostly to broad employers whether or not you noticed, because they publish four out of every five listings.
How we measured it (and what we did not claim)
We grouped active listings by employer, normalising for case so that variants of the same name are not counted as separate companies, and excluded aggregator accounts where a job board name had been recorded in the employer field. That exclusion matters: before it, one job board appeared as the employer of 1,807 listings across 22 domains, which would have made it look like the most functionally diverse employer in the corpus. Industry labels come from our own classifier rather than from the employer. Concentration is measured on listing counts, not on hires, headcount or openings, and a listing is not an opening: some employers post one listing per location for the same role, which inflates their share relative to employers who post once. That effect is stronger in healthcare than anywhere else, so read healthcare 49.3% as the ceiling of a range rather than a precise figure. What the comparison between industries supports is the relative shape, which holds regardless of that bias because it applies to every employer in every industry.
Frequently asked questions
Should I apply to lots of jobs or target specific companies?
It depends on your field, and the difference is large. In healthcare the ten largest employers post 49.3% of listings, so targeting them deeply covers half the market. In marketing they post 12.4%, in sales 13.5% and in design 15.7%, so breadth of search matters far more. Engineering sits in between at 22.5%.
Which employers hire across the most different functions?
Amazon spans 20 functional domains with 21,501 active listings, followed by Apple at 19, Johnson and Johnson at 19, Google at 18 and JPMorgan Chase at 17. Only 13.7% of the 27,544 employers we measured hire across five or more functions, though those employers hold 79.2% of all listings.
Can I change careers without changing employers?
For most employers, no. 52.2% post in only one functional domain, so there is no internal move available to make. The 13.7% that hire across five or more functions are where an internal function change is structurally possible, and they are nameable rather than hypothetical.
See where you stand
Upload your resume to see your skill gaps, match scores, and which roles fit your background.
Analyze my resumeRelated Data
We Analyzed 1,835 “Entry-Level” Job Postings. Most Still Demand Experience.
“Entry-level” / junior postings analyzed: 1,835
The Highest-Paid Skills in 2026, From 73,374 Job Postings That Disclosed Pay
US postings with disclosed pay analyzed: 73,374
Backend Engineer Market: What 200,000 Job Listings Tell Us
Active backend roles: 24,600+
The 25 Fastest-Growing Skills in 2026 Job Postings
Jobs analyzed: 133,000+
Guides
Data derived from Seeker's job corpus of 231,147+ listings across multiple sources. Updated 2026-07-21. Individual results vary based on resume content, target market, and role specifics.