Does anyone understand Amazon bestseller rankings? 
Out of the Mist, our (Evergreen Writers Group) anthology of ghost stories had spikes in its e-book bestseller ranking on Amazon.ca on May 5, May 31 when it reached #4 in the short story grouping, and June 8. We also had a spike in our paperback sales on May 22, but I think I understand that one.
During that period we had no e-book sales, nor any free book promotions or anything else that might have generated 'sales' and improved rankings without bringing in any revenue.
So how did we get to number four on the rankings for short stories ahead of Carol Shields, Madeleine Thein, Margaret Atwood and Alice Monroe? I know it was only a few days, but it felt good to be momentarily ahead of those well-known authors.
I just wish I knew how the rankings worked.