Unless they own their own flying field, having an AMA charter will bring "site owners" insurance that will cover the owner of record of the property.

As am AMA charter club you also have club insurance that covers "non-flying" events (i.e., mall shows, convention shows, etc). Many malls (halls, etc) will want a proof of insurance certificate for at least 1 or 1.5 million dollars before you can set foot in the place.

Dan