Carpet purchases from most reputable dealers carry some form of warranty. These warranties can last from one to twenty years and even the entire time a homeowner owns the house. The manufacturers also carry their own warranties as well.
What many homeowners are not aware of is that in order to maintain their warranty their carpets must be cleaned by professionals on a regular basis.
Most every carpet manufacturer requires carpets to have a restorative cleaning which is accomplished by hot water extraction. A reputable carpet cleaning company should document and be able to provide your cleaning history if asked.