Spots are the marks left on carpet after oils or liquids have been spilt onto the carpet. The liquid attracts the dirt to the carpet fibre and dark patches appear as a result. The dirt does not actually penetrate the fibre. These types of spots are usually removed during the carpet cleaning process and there is no extra charge to remove them. High traffic areas usually attract a lot of these types of dirty spots or marks on carpet. This is why we always pre spray and use a spot remover before we clean the carpet. Visit - https://www.blackgoldcarpetcleaning.com.au/spots-and-stains/