In the middle of recession style "your raise this year is the fact that you still have a job", a 5% raise would earn you a lot of loyalty... and a 10% raise is stuff of legend.
A 10% raise for a department is cheap: say the business laid off 10 people in the department over the last 4 years, and 3 people remain to run a formerly (about) dozen person department. So you're spending 1/3rd of an average salary to keep those people on. Compared to the 20% a headhunter would take + the productivity loss of replacing workers... sounds like a deal to me.