Most people don't realize that guitar strings are not designed to last like violin strings or piano strings. If you get 5-8 weeks out of a set of strings, you're good. For the casual player, two months is about the limit (three to four months if you purchase Elixirs or some other extended life strings). The only exception to this are 80/20 Bronze acoustic strings, which provide the brightest sound on an acoustic guitar but last only 5-10 days. Being more affordable, 80/20 bronze is perfect for the professional acoustic guitarist playing many gigs during the week who change their strings more frequently. The reason guitar strings last for a small amount of time is due to their construction. Nickel or bronze is wound around a steel core, depending on the guitar you use. Although the windings are quite compact, acids and dirt from play and the environment settle within the windings and reach the core, ultimately corroding it. Some players have such corrosive oils in their hands, that they can kill a set of strings within a week or even days
(another reason why coated or chemically treated strings are a good buy). Strings will also stretch too much from being at tension for too long. This can lead to buzzing and deceive the player into believing that their guitar needs a set up when, in fact, a new set of strings is all they need.
