Ick....I hate sticky doorknobs, and finger printed mirrors, light switches and windows. I venture through my house daily, with a towel, moistened with cleaner, and scrub and scrub. I do the windows almost daily around here. I am always surprised to come around the corner to note a window or mirror with kiss marks on it, or a trail of saliva. "mirror licking" an apparent great way to spend the morning. Gross.
On the other hand, my in-laws love the baby prints, and kiss marks...And when we visit they NEVER clean the baby prints off of the mirrors and windows. Even those with cleaning ladies know better than to wipe the bottom 4 feet of mirror or glass in any of the homes.