Some casinos mail offers are completely free...others come from your comp account. Harrah's is free, Atlantis Reno are free, Peppermill Reno come from your comps. Quite often, casinos that charge your comp account for mailer offers have higher comp rates to compensate (i.e., Peppermill Reno has a more generous comp forumla than Atlantis in Reno). Even though these mailer offers sometimes come from comps, they can still be considered "free" because the casino will give you the offer regardless of how far in the negative your comp balance is. Also, if you put in good action, hosts can sometimes override the system either with discretionay account comps OR just drive your account further into the negative. Stay on the mailer offer and play elsewhere for meals.
SDM