I used to own a small housecleaning business, with myself and four members of staff doing the work. Our approach was pretty much the same as what Portable detailed a couple of posts up. We charged a professional rate, and made sure we did a professional job. We had a meeting with every new client before taking on the work, which involved a detailed walk-through of the entire house. This allowed us to tailor the service to the customer's needs, manage expectations (only when everyone is singing from the same hymn sheet will both sides be happy with the arrangement), and address any questions or concerns. Plus we could discuss pricing in person, having seen exactly what we were getting into. Never, ever would we give prices over the phone or on our website.
The vast majority of our clients were executives or self employed working 60+ hours a week. I wouldn't call them lazy for not wanting to come home at 9 PM and start cleaning a six bedroom house. We also had some elderly and disabled customers, who needed a little extra help with certain tasks. For them, it made all the difference between keeping on top of things and maintaining their independence, versus not coping fully and allowing things to go to rack and ruin. Again, not lazy.
Now the only ones I didn't have any time for were the desperate housewives who only wanted a cleaner for the sake of having one. Wildly unrealistic expectations, and usually under the false impression that they could set our prices for us. Also the most likely to talk down to our staff, because he or she was "just the cleaner". We got to be quite good at weeding these ones out from the start, and declining their business with the polite excuse of being fully booked.
Personally, I always preferred to clean when I had the house to myself. No interruptions, and no fear of disturbing the client or making them feel as though they had to keep out of my way. Sometimes though it was unavoidable, for example when they couldn't get into the office and had to work from home. One thing I would never do, however, is snoop amongst their belongings or help myself to the contents of their fridge. That's just creepy, and I'd hate to be on the receiving end of it.
If you do employ a cleaner, I'd say the most important quality to look for is someone who actually enjoys cleaning. You don't want someone in your house who resents doing other people's dirty work, because that's basically what the job is all about. Make sure they have full insurance, and if possible, ask to speak to some of their other clients. A good cleaner will advertise very little (other than when first starting up business), because most of their work comes in through word of mouth recommendation.
These days I'm in a completely different job, working 12 hour night shifts, but I still do my own cleaning. This does eat into my free time a little, as I like the place to be absolutely spotless at all times. Given the hours I work I wouldn't feel at all guilty for hiring a cleaner if that's what I wanted to do, the only thing stopping me is the fact I get satisfaction out of doing it myself.