CareerXroads' 8th Annual Source of Hire study offers some insight into the way corporations fill their open positions -- and how they measure and report sources of hire.

Among its findings:

* Internal transfers and promotions were nearly 40 percent of all full-time company fills.

* Referrals made up slightly more than one-quarter of external hires.

* Hirings pursuant to job-board listings were 12 percent of external hires -- a number that CareerXroads believes is at its peak.

The full report is here.