[BenG]

I mainly use Goodreads to tracks books I've read and those I remember reading going back to childhood. I mainly just use the star rating as defined by Goodreads : 5 stars= "loved it", 1 star="didn't like it.
But some people try rate by objective quality, so you have a mix of rating philosophies on the site.

Also the actual definitions of the different ratings are different from what people normally perceive; 2 stars="it was ok" but most people think of 3 stars as average.

I don't usually use the site to look for books to read (except for other books by the same author) but sometimes a book will catch my eye.