One reason to hire a professional, large office cleaning company for your business is staffing. Because these companies have many people on their payroll, should one not show up for work, you know they will have another person come out instead in their replace. In some businesses, this may not be the case.
Office cleaning professionals often will have different requirements and needs to be met. If you are looking for one, consider the choices you have in these differences. If they have a package that comes with everything you need, great. But, if they do not do something that you know you need to have done, they aren't worth the investment to you.