So what is the importance of vacuuming?
Never has the importance of vacuuming been more relevant to building maintenance than today. Keeping the soil load down is the key to a healthier indoor environment. Too many times this is where corners are cut. Not enough people to do the cleaning, budget does not exist or the right type of vacuum is not being used with the right frequencies.
About 87% of all foreign particulate in the carpet can be removed using a vacuum cleaner. Soil that builds up in the carpet can cut and scrape fibers damaging there use life and appearance. Dull & Uglied out carpets are the result. Does not matter if you have wool (natural fibers) or nylon (synthetic fibers).. All can be negatively effected by soil build up.
So what does the industry recommend? The Carpet and Rug Institute has frequency recommendations. 
- Vacuum daily in high-traffic.
- Vacuum twice weekly in medium-traffic areas.
- Vacuum weekly in light-traffic areas, using attachments at carpet edges.
Whether you are using a restorative hot water extraction rinse or interim encapsulation methods vacuuming should be done prior to cleaning by either the in house staff or the professional cleaning company.
Walk off mats can help to collect the soil prior to entering the building. Interior and exterior mats are available. Buy good mats. The less expensive ones tend to not last long and can not handle heavy traffic.
When no walk off mats are placed at entrances, in garages, in kitchens, etc the carpet pays the price. Often vacuuming in these areas are considered to be high traffic and could be vacuumed multiple times per day.