This is one of the most asked questions we receive at Knockout. We answer with all honesty, and that is “it depends on your situation”. If you take your shoes off, have no kids or pets, and vacuum frequently, then you can go two years easily without needing a professional. But, at the opposite end, if you and your family of kids do not take your shoes off, and have pets, and do not vacuum as frequently as you should, we have seen some customers every 90 days. So, to answer this question, it depends on how you see your carpets, and important it is, to not only look clean, but be healthy as well. If you have allergy sufferers, regardless of house hold members, regular cleaning also helps eliminate dust mites, pollens, animal dander, and other allergy-causing agents. We at Knockout recommend at least, take your shoes off before walking on carpet, because not only does shoes bring in dirt, and allergens, shoes also damage carpet by rubbing small dirt particles against the fiber, and scratching it, causing it to look grey at first, and eventually dark. When carpet becomes damaged, cleaning cannot help bring it back to other then light gray. We also, recommend a good vacuum cleaner, that had a brush that agitates the carpet, and brings the small soil to the surface. These small practices, can really extend the life of your carpet, and if practiced frequently, extend the necessary professional carpet cleaning. For our existing customers, we of course send out reminder cards, for you to look at your carpets, and see if they need to be cleaned.