The commercialization of copylefted works differs from proprietary works. The economic focus tends to be on the commercialization of other scarcities, and complimentary goods rather than the free works themselves. One way to make money with copylefted works is to sell consultancy and support to the users of the work.[1] Generally, financial profit is expected to be much lower in a business model utilising copyleft works only than in a business using proprietary works.[2][opinion][better source needed] Another way is to use the copylefted work as a commodity tool or component to provide a service or product. Android phones, for example, include the Linux kernel, which is copylefted. Unlike business models which commercialize copylefted works only, businesses which deal with proprietary products can make money by exclusive sales, single and transferable ownership[citation needed], and litigation rights[citation needed] over the work, although some view these methods as monopolistic and unethical, such as those in the Free Software Movement[citation needed] and the Free Culture Movement[citation needed].
