Although many of us spent our teens and early 20s getting very familiar with the business services companies known as temp agencies, they're more than just a way to make ends meet over the summer or between jobs.

These days, business services companies provide not just administrative labor, but professionally skilled labor and back-end support (like payroll) as well.

In an era of ever-more-flexible work environments, these companies enable both workers and companies to do what they need to do.

Getting into the numbers
Who are the major business services companies and how do they stack up to one another? Remember that while Administaff, Automatic Data Processing and Paychex specialize in outsourcing payroll, human resources, and benefits so companies can focus on doing what they do best, companies like Manpower and Kelly Services specialize in matching skills with needs.

Company

Market Cap (in millions)

Revenue, LTM (in millions)

Free Cash Flow, LTM (in millions)

CAPS Rating

Automatic Data Processing (Nasdaq: ADP)

$21,070

$8,867

$1,592

****

Paychex (Nasdaq: PAYX)

$10,203

$2,001

$576

****

Manpower (NYSE: MAN)

$3,584

$16,495

$88

***

Administaff (NYSE: ASF)

$622

$1,649

$52

**

Kelly Services (Nasdaq: KELYA)

$513

$4,403

($74)

**

SFN Group (NYSE: SFN)

$362

$1,748

$31

***

Barrett Business Services (Nasdaq: BBSI)

$136

$244

$2

*****

Data from Capital IQ (a division of Standard & Poor's), and the Motley Fool CAPS database. LTM = Last 12 months.

Which business services company do you like and why? Let us know in the comments area below.

Fool editor Julie Clarenbach doesn't own any of the companies mentioned here. Administaff and Paychex are Motley Fool Inside Value picks. Automatic Data Processing and Paychex are Motley Fool Income Investor recommendations. Try any of our Foolish newsletters today, free for 30 days. The Motley Fool has a disclosure policy.