Many homeowners make the mistake of assuming their carpet and furniture are clean just because they look clean. What they may not realize is that, over time, even the most spotless looking carpets and upholstery soil quite evenly and lose their original luster. They also collect dust and soil below the surface where regular vacuum cleaning may not reach. To increase the useful life of your carpets, most carpet manufacturers recommend you have carpets cleaned every 12-18 months before you may recognize they are dirty.