For the average collector who buys the majority of books from home, it's nice to see approximately how many books have sold and when... PQ and all, and for what price - only to use as a basis for making a decision.
It seems easier than sifting through ten different websites, calling ten different dealers, talking to other collectors and going to 6 cons a year to get a feel for prices.
I'm aware that we don't live in a perfect world so not everyone will report, but GPA's business is selling info and the more accurate the better.
I'm interested to know... as a private dealer, if GPA paid you every month, would you report sales info to them?
I get that it takes time and energy to report.