90% is dirt, the rest fall into the categories of mishandling or defects. Very few LPs just simply wear out with play, unless played with cheap and/or poorly aligned stylus.
Back to basics
I would like to understand the process that deteriorates the surface of an LP and makes those "pops" and "clicks" appears forever. I know that there is friction involved when the stylus runs across the LP but will be great to go deeper (for example how interacts the stylus and LP materials and how that creates the problems that I mention -if thats the origin of those problems-). If there is a link where I can find what Im looking for will be perfect to know where to go.