OF the different type of customers there are at least two: cheap charley's and people who want great results. I agree the need for wall repair is critical to the end results. Most critical is for the customer to be told ahead that the walls are going to need exactly what is needed. This means the contractor must look, touch, examine the walls for defects and needed work. I've been a building manager for 40 years and seen a few paint jobs. Typically a contractor does a lot of talking about how expert he is, but the guys who walk through with note pads, iPads, examine, measure, point things out, explain and recommend are the ones I will deal with. It confirms if they know what the business. Nobody likes the workers to show up and when you talk about the job they're going to do they know nothing but they we were told to be here. Their boss who bid the job doesn't supervise - a big no no around here. Nobody likes surprises or worse, at the end of a job that's not right getting a bunch of little kid excuses. Contractors that do not like the customer to be around looking at the progress don't get the job.
To win work, contractors generally have to bid against other suppliers. To make an accurate bid, they estimate the time and materials required to complete the job. They measure the area to be painted and discuss the type of finish the customer requires. They assess the quality of the surfaces to work out how much remedial work they must carry out before painting. They might have to remove old paint or wall coverings, or repair cracks and other damage. They also calculate the cost of any essential equipment, such as scaffolding for exterior walls.
Thorough preparation is essential to ensure a good finish. Contractors might have to fill cracks or holes and remove old paint if it is badly worn, peeling or flaking. They remove all paint and apply a suitable primer to the bare surface. If the existing paint is in reasonable condition, they clean it and rub it with abrasive material to provide a key for the new paint. On new surfaces, such as bare wood or fresh plaster, they apply a suitable seal, followed by a primer coat.