This is certainly one of the most common questions that we receive. The proper answer is really that it's different for everyone. The first thing to consider is if you have purchased new carpet and are concerned about keeping the warranty. If so, most companies require that you have a professional company perform Hot Water Extraction carpet cleaning (which is the method we use) every 12 or 18 months. If you don't do so, they will usually void the warranty.
Secondly, consider the use of your home or office. If you have a home with multiple pets, small children, and lots of get togethers, you should consider cleaning every 6 months. If your home or office is only used by a few people, no pets or children, and you take your shoes off at the door, every year and a half will be sufficient. As always, we will offer to do a free inspection for carpet, upholstery or tile cleaning, as well as give you our advice!