I love stats on what it's going to take to steal your talent from a comp perspective.  Latest data is from Salary.com via the Working section of the Washington Post:

"If you're like many employees, you'd expect at least 16 percent more money to jump ship. 

More than one-third of workers would move for a 16 to 30 percent raise, according to a Salary.com survey. Another third would walk for 8 to 15 percent more in the pay envelope. And one in six said it would take a raise of 31 to 50 percent.

Oddly, most employers think it would take less -- 15 percent or less -- to lure away talent.

And employers offer, on average, only 7 percent to persuade a valued employee to stay. Half of employers said they sometimes make counteroffers, but more than a third said they never do."

I think those numbers ring pretty true.  Here's how I get my head around it:

1.  The chronically unhappy or those in danger of losing their job will leave for a lateral pay move or a very small bump.  This number is broken out in the above numbers, but based on the other figures, this is about 20% of the average workforce.

2.  Those who are at least somewhat content by open to hearing the message from recruiters?  The bidding starts with the equivalent of a promotional pay bump, which is the 8 to 15% group.  That's a third of those surveyed...

3.  Those who are happy and content?  They're still willing to listen, but like the Godfather, you'll have to make them an offer they can't refuse - a 16 to 30% bump in pay    (33%) or maybe more than a 30% increase (16% of those surveyed).  So that equals 50% of the workforce.

So the bottom line for those of you following at home...  About 50% of workers are available for the equivalent of a promotional increase.  The rest will be more expensive.

Of course, as with all data coming from Salary.com, it's self-reported data.  Raise your hand if you've ever had an employee print out data from a job that didn't match the one they were in and present it to you as scientific comp data showing a pay issue on their behalf....