$500 IRG Participation Charge

I was thinking of getting a C-class, and when I look at the bottom of the invoice there's a $500 IRG participation charge... anyone know what that is? Thanks

[terminator]

It is a mandatory advertising charge that all dealers must pay to Mercedes Benz. This is how the national ads are paid for.

Terminator

02 C240W
89 300SEL
83 300TD
82 240D (SOLD)
83 240D (SOLD)
83 380SL (SOLD)
84 300SD (SOLD)
86 560SEL (SOLD)
88 300SEL (SOLD)
95 E320A (SOLD)