How long a carpet will last depends on the quality of the product, the amount of traffic/use it experiences, and how well it is maintained.
Almost every product found in a Flooring America/Flooring Canada showroom will have a star-level warranty that will indicate how long the carpet is warrantied against wear & texture loss if it is properly maintained under normal traffic.
Carpet products with a 1-star warranty are warrantied for 5 years, 5-star products are warrantied for up to 25 years. Proper maintenance to ensure you get the most out of your carpet includes regular vacuuming (once per week for every person who uses the room), using floor mats in exterior entry-ways, and getting your carpet professional hot-water extraction cleaned every 12-18 months.
It is also important to address any stains on the carpet immediately with one of the recommended cleaning methods in your carpet warranty guide. Many of the carpet products sold at Flooring America/Flooring Canada can outlast their warranties if used and maintained properly.