Most chiefs will not want area businesses to give discounts/free items to their officers/deputies. They are afraid that those that receive them will show favoritism towards those businesses, taking attention away from a police presence in other businesses that do not offer such discounts. In a weird round about way, they don't want it come off looking like a bribe for cops to hang around.
As a member of law enforcement, I have no problem with receiving a discount, as I know businesses do it as a "thank you" to those of us who serve our communities.
However, I also never expect a discount, and I would certainly never write a company demanding one. We chose our profession, and we know the risk. I witnessed a fellow officer's funeral this past summer after he was shot and killed after getting out of his squad car. It's something that crosses our minds every day, but it never stops us from doing our job.