While carpet manufacturers recommend having most types of carpet cleaned every 4-6 months, I’ve found that all households are different, thereby requiring different cleaning cycles. Time, more than anything else, can make the most common, easy to clean stains permanent.
  If you happen to have a solid very light colored carpet, coupled with an “active” household, I’d recommend a 4 month cleaning cycle. In a home with minimal traffic, you might get away with every 6-9 month cleanings.
 Purchasing a small exractor type device(spotter)can go a long way in saving the expense of hiring a company to clean your carpets. Acting quickly after a spill, or pet accident is key to keeping carpet looking new. If access to cleaning solutions/devices is delayed, try to blot up as much of the area as possible, then try to keep it damp til help is on the way.
  Traffic areas are always the most difficult and problematic areas in a home with carpet. Some high traffic areas are also pivot points, a juncture where you tend to twist your foot to change direction. These areas are most prone to “greying”, which is essentially a carpets color fading and experiencing a high volume of foot traffic. It is important to vacuum these areas frequently as the build up dust/debris in these areas will cause these areas to wear incredibly fast. It is not uncommon for a room, or entire house of carpeting be replaced because of the fading and wear in these high traffic, pivot areas, which probably only equal 10-15% of the entire carpeting in the home.