Non-smoking rooms are in more demand daily. Get on the bandwagon and provide more smoke-free rooms--or floors--for your guests. In fact, take it a step further by making the entire property smoke-free. Your guests will benefit because they will feel healthier and their clothes won't reek of tobacco smoke. You will benefit because you will attract more guests, you won't have to move guests to rooms that are satisfactory to them, and you won't have to go the effort and expense of cleaning a room that's been smoked in.
Rooms that have been smoked in can cause severe problems for people with allergies or sensitivities. You don't want to lose that business, and you don't want to send any of your guests to the hospital with breathing problems. Westin was the first major hotel chain to ban smoking in all of its properties in 2006, and many more chains and individual properties have followed suit since. A number of states have banned smoking in all hotel rooms due to the risks associated with second-hand smoke.
Smoke residue embeds itself in all surfaces, making it virtually impossible to clean the room. The oils slowly destroy the fibers and materials they are embedded in, which means you have to replace curtains, carpet, upholstery, and wall surfaces more often than you otherwise would.