We do CV because it falls under the 'low volt' umbrella. Since we do tv/tel, security, cctv, etc for builders (so we can get our foot in the door and sell multi room audio, control systems, and theaters) we also do cv. It is easy, just get a can rated for 35- 40% more square footage than the house and you will always be fine. Drilling the holes sucks, and you won't profit much form it alone, but if it helps you get builders or increases your appeal as a one stop shop for customers then it is profitable indirectly.