Sure sounds like employee leasing....
What and how are you paying them?
A % of payroll or a flat rate per employee?
Here's some food for thought:
Just found something in State of Nebraska Unemployment Tax stating "a leasee of an employee leasing company shall be held liable for state unemployment taxes if the employee leasing company fails to pay"....
Know what the laws are in your state pertaining to these arrangements.. More than one good company has been burned by an employee leasing company.