I'm a massive stats nerd with spreadsheets for practically everything. This morning I was playing around and work this out. I sell bugger all and at the moment I only put short stories on free promo rather than whole novels (although part one of my novel Tube Riders is currently free though I can't be bothered to post the link). However, my frees to sales ration is currently a fraction over 32 frees per sale.
Obviously there are a billion factors to consider, such as genre, general laziness of your audience, number of reviews, number of separate works available, etc, but I reckon in theory if the presets are the same this figure can tell you how good a writer you are. The lower the better, obviously.
All of the fourteen works I have up on Amazon are genre fiction, that is sci-fi, horror and fantasy. So, what's your ratio? Who's asses am I kicking and who is kicking mine?
I've had 3 2-day weekends, and two single days, all about a month apart (except the first single day), meaning I've got one 2-day weekend left in my second 90 days, which will be in July sometime. Twice I was in the top 10 of free books; once at #2. The biggest weekend was in March, and netted over 19,000 downloads in 48 hours. All I can figure is that people who download free books on the weekend mostly like cats, glance at the good reviews, and make a snap judgement.
Until Amazon changed the way free books count toward rank in March, I was hovering in the top 5 of humor, #1 in "last 90 days," etc. But now all those free downloads don't seem to mean anything, beyond a temporary burst in sales for a few days after it ends. My "normal" sales--more than a week away from any promo--seem to be about 9-10/day. One thing I will say for recent promos, is that finally increased my UK sales. But I am writing a sequel, and perhaps a series, and I hope all those free readers come back for another taste.
Guess we'll see. At least all the frees resulted in many more reviews than my sales would otherwise justify (62 at present count, with over 40 5-star and most of the rest 4-star).
I should add that the first two months my price was 99 cents, and the day after a big free weekend, I'd sell hundreds of copies--once 1,000--which helped drive my overall free/sale ratio. After I raised the price to $2.99, my day-after-promo sales have been just 75-100.
Overall I'm about 3 free to 1 sale, that's with a book that's been free since Oct. Oddly enough, the majority of the sales are for a book that's not part of the series the freebie is from, the free/sales ratio for that series is more like 8-1, although I don't have complete freebie figures because ARe doesn't report on free sales, so I've had a best guess based on the book's ranking compared with the paid copies (because they are ranked equally on ARe). May be more like 4-1 and 10-1. High point for the freebie was the first weekend on Amazon when it hit #120 in the store, these days it hovers around 4-5k and I'm making moves to take it off free in the next couple of months.