My husband's stepmom is middle-eastern (we're as white as you can get) and I also know many other middle-eastern and asian households that never wear their shoes in their house. I just figured taking shoes off when entering the home was a cultural custom. Maybe I'm wrong. Anyway, I think most people do not wear their shoes in the house mainly to help keep the floors clean. Not even for the sanitary part but just all the extra dirt brought in from the playground, gum (or worse) stuck on the bottom of the shoe, etc. Cuts down on sweeping and vacuuming. I will say that when I have a casual, neighborhood party (such as child's b-day party), everyone just kind of knows to take off their shoes. I usually leave a hint by lining up a couple pairs of shoes by the front door along with a towel for guests to put their shoes on. But if I am hosting a formal party, I do not "enforce" the no shoe rule. For example, when I hosted a surprise retirement party for my dad, I was not about to ask his co-workers to take off their shoes . . . I guess respect for elders as well as kind of looking silly in nice dresses and slacks and walking around in just socks or pantyhose

Also, my mom has foot/anlke problems and despite the face that she lives on a farm and walks around in the pastures with the same shoes that hit my floor, I won't ask her to take them off because I know her feet will hurt if she takes them off. Once again, the respect for elders thing.