[georgiecasey]

I think he's referring to traders paying for colocation in the exchange data centre.

[osrec]

Precisely, and money isn't the only factor here. Your contacts, your firm's contacts and your trade volumes (amongst other things) can get result in you getting preferential treatment.

[gumby]

Thanks, I could not see that implication. I guess it shows what field I do not work in :-)