How Do Staffing Agencies Fill Large Volumes of Roles Every Month? The Refill Engine and What Its Markup Costs per Hire

Staffing agencies fill large volumes of roles every month mainly by refilling the same seats, not by finding brand new demand. In 2025, America’s staffing companies employed nearly 2.0 million temporary and contract workers in an average week but hired 9.5 million over the year, according to the American Staffing Association. That is roughly 4.75 hires for every seat filled in an average week.

The machine that makes this possible is paid for by the client through an hourly markup on the worker’s wage. That markup buys you something real: the agency carries the cost of every quit, no show and refill. It also means your recruiting cost scales with hours worked, not with hires made, which is the number a budget holder needs to understand before comparing an agency against hiring direct.

How do staffing agencies fill so many roles every month?

Five mechanisms do most of the work. None of them is secret, and each one has a cost that lands somewhere in the bill rate.

1. A redeployable pool. People who finish one assignment are offered the next. The American Staffing Association reports that 64 percent of staffing employees work in the industry to fill the gap between jobs or to help them land a job, which keeps a steady stream of returning candidates in the agency’s database.

2. Always on attraction. Agencies advertise continuously for job families such as warehouse associate or forklift operator rather than one requisition at a time, so a pipeline exists before the client order arrives.

3. One onboarding, many assignments. The agency is the employer of record. A worker who has already been screened, hired and set up on payroll can be placed again without repeating that work.

4. Hourly pricing that funds the engine. Every hour billed carries a markup, and that recurring margin pays for the pool, the advertising and the recruiters.

5. Contract terms on fill and replacement. Client agreements typically set how fast orders must be filled and what happens when a worker leaves, which turns refill into the agency’s problem instead of yours.

How much of that volume is refill rather than new demand?

Most of it. The 9.5 million hires against 2.0 million average weekly workers in 2025 ASA data means a typical seat changed hands several times in the year. ASA’s own turnover method divides people employed by average weekly employment and subtracts 100, which on those national figures gives a turnover rate of about 375 percent.

Industrial work is the single largest slice. ASA puts 36 percent of staffing employees in industrial occupations, ahead of office and administrative roles at 24 percent. On the federal side, the Bureau of Labor Statistics counted 2,486,800 jobs in temporary help services in September 2026, seasonally adjusted and preliminary.

For a Head of Talent Acquisition, the implication is direct. When an agency says it fills 500 roles a month for a client, a large share of those fills are replacements for people who left earlier placements. The capacity is real, but it exists because turnover is built into the model.

What does the staffing markup pay for, per hour?

The cleanest public view of markup pricing comes from procurement documents. Boise State University’s temporary labor and staffing page explains that the department chooses the pay rate, multiplies it by the vendor’s percentage markup, and is invoiced the result per hour. The commercial and industrial markups listed for vendors on that contract range from 24 percent to 28 percent.

Here is that structure applied to a common frontline role. The Bureau of Labor Statistics reports a median annual wage of $38,220 for hand laborers and material movers in May 2025, which is about $18.38 an hour over 2,080 hours. The 26 percent markup below is an assumption taken from the middle of the Boise State range.

The $1.41 line comes from the employer share of payroll taxes: 6.2 percent for Social Security and 1.45 percent for Medicare, per the IRS. You would pay that tax yourself as a direct employer, so it is not a staffing premium. The $3.37 is where recruiting, refill and the agency’s margin live, alongside other statutory costs that also apply to direct employers.

For context on the full cost of a direct employee, the Bureau of Labor Statistics reports that benefits made up 30.0 percent of private industry employer compensation costs in June 2026. A fair comparison therefore weighs the agency markup against your own loaded cost and recruiting cost, not against the wage alone.

Who carries the risk when workers quit or do not show?

Under an hourly markup, the agency carries most of the volume and conversion risk. If a worker quits after two weeks, the agency recruits, screens and places the replacement, and you pay only for hours actually worked. If your site needs 20 percent fewer hours in a slow month, the invoice falls by 20 percent because it is priced per hour.

That flexibility is the strongest argument for staffing in seasonal or unpredictable demand. You are not prepaying for recruiting capacity you might not use, and nobody bills you for a candidate who never arrived.

The trade sits on the other side of the ledger. The markup is charged on every hour, including the hours worked by someone who stays for a year and never needed replacing. Your recruiting cost is therefore tied to hours, not to the number of people the agency actually had to find.

What does a staffing agency hire cost you per person?

Divide the annual markup by the number of people actually hired into your seats. The example below uses 100 seats filled for a full year at the rates above, which produces about $994,000 of annual markup, of which about $701,000 remains after employer Social Security and Medicare.

The pattern is counterintuitive. The better your retention, the more you pay per person the agency actually recruited, because the hourly markup keeps running while the agency’s refill work falls. At the industry’s average churn the per hire figure looks efficient. At a well run site with stable crews, the same contract becomes an expensive way to buy recruitment.

When does an agency beat hiring direct, and when does it not?

Staffing tends to win when hours swing hard by season, when assignments are short by design, and when you lack the recruiting team to absorb sudden orders. In those conditions the agency’s pool and its willingness to carry refill risk are worth the markup.

Hiring direct tends to win when seats are stable, tenure is long, and you can run your own attraction and screening. In that case the cost you want to control is cost per qualified applicant and cost per hire, not cost per hour.

Before signing or renewing an agency agreement, ask five questions in writing:

1. What is the markup by job category, and what does it include?

2. Is there a conversion fee if you hire a worker directly, and after how many hours does it fall away?

3. What fill rate and time to fill does the agency commit to?

4. Who pays when a placed worker leaves in the first weeks?

5. Does the markup change when the pay rate rises, so that a wage increase also raises the agency’s margin?

Where does Wonderkind fit if you hire direct?

Wonderkind fits the direct hiring side of this decision, where an employer or a staffing firm runs its own attraction and wants the recruiting cost tied to an outcome rather than to hours worked. Its pricing page describes a performance budget in which the buyer chooses “a click, a lead, or a qualified applicant” and sets a target price, with the budget deploying across channels and optimizing toward that price.

The qualified applicant unit is defined in Wonderkind’s terms: a candidate who completes the application flow, passes the knock out questions the customer configured, meets the customer’s job description criteria, and is delivered into the customer’s ATS, with all four conditions required. That moves conversion risk at the top of the funnel to the vendor, much as an agency carries refill risk. The trade off is that you still employ, onboard and retain the worker yourself, so the model only beats a markup when your retention is good enough to make hourly pricing the more expensive way to pay for recruitment.

Frequently asked questions

How many workers do staffing agencies hire in a year?

America’s staffing companies hired 9.5 million temporary and contract employees during 2025, while nearly 2.0 million worked for them in an average week, according to the American Staffing Association.

What markup do staffing agencies charge for industrial workers?

It varies by contract and category. One public example, the vendor list on Boise State University’s temporary staffing page, shows commercial and industrial markups between 24 percent and 28 percent on the pay rate.

Is a staffing markup the same as a recruiting fee?

No. The markup also covers employer payroll taxes and other employment costs the agency carries as employer of record. Only the remainder pays for recruiting, refill, administration and margin.

When is a staffing agency cheaper than hiring direct?

Usually when demand swings by season and turnover is high, because the agency carries refill and you pay only for hours worked. With stable seats and long tenure, the hourly markup tends to cost more per person actually recruited.