The method does not change between sectors, but the priorities do. A home services business usually loses more revenue to missed calls than to a shortage of enquiries. A professional services firm has the opposite problem. Getting that order right is most of the value.
Editor note — replace before launch. These industry pages describe the shape of the problem in each sector. They do not claim experience. Delete any sector you have not genuinely worked in, and add case studies to the ones you have.