What is the purpose exactly of the slabfree pledge?

The purpose of the slabfree pledge is to let slabbing companies and dealers who sell slabbed chips know that we are prepared to vote with our dollars. Very simple really. These 3 lines of the pledge spell it out to any dealer considering selling slabs.

I will NOT buy ANY chip from any dealer who sells slabbed chips.
I will NOT buy ANY chip from any dealer who grades chips for a slabbing service.
I will NOT do business of any kind with any dealer who participates in any way in the slabbing of chips.