So what effect does a free promotion have?

Over my three-day promotion, which ended at midnight California time, a total of 1248 books were downloaded. All but 13 from amazon.com, .co.uk, and .de . During the promo, Despite the Angels rose and fell, its highest ranking of free books was #455, which was at 2.15pm Irish time on Sunday. It hit a high point of first place in 'Romance-paranormal-ghosts' for a few hours, and then settled to #3. This was a little mystifying, as there are no ghosts at all in the book!
I decided eventually that someone in Amazon must have seen the phrase 'spirit guides' and latched on to 'spirit'. But of course spirit guides are definitely not ghosts!
The book also got up to 8th position in 'romance-paranormal-angels'.
All that is of no importance really, it is what happens now that is of significance. And sadly, that is not likely to amount to much. The book is at 315,003rd overall in amazon. This is probably about half way up, but it is still totally invisible. It would be similar to your book being stocked by a big bookshop, but left in the storeroom!
People who specifically look for either ghost or angel books may stumble across it, at #204 out of 1399 for ghost, and #128 out of 633 for angels; but looking at the others in those lists (only the covers, admittedly) made me feel they were not attracting the readers who would want and enjoy my kind of angels!
So I have more research to do, to work out where to market it next. if any of you have read "Despite the Angels" and are familiar with Amazon's genre selections, maybe you would be kind and give me your opinion?