I've enrolled several of my books, and whilst I haven't experienced such a massive increase as yourself, I found my total sales increased quite reasonably.

I suppose it's down to the 'also bought' exposure from Amazon and to increased exposure of my name from free downloads. Whatever, I'm glad I took the tentative step,

Indeed, Doug, the question we are all fielding is whether or not sales will level after naturally falling some, and then gradually increase, or just return to the mean with no long term impact. I too have seen a marked jump in all my sales, which has tapered off, leaving me at roughly double my pre-freebie overall volume. Interestingly, my pet book, An Angel With Fur, saw a huge increase, and then trickled back to about three times normal sales. The Geronimo Breach is quadruple pre-free levels, and looks like it's stabilized for now, even like you, after increasing the price. The others are maybe up 50%. So on balance, the experiment was good from a visibility standpoint, but I suspect there are no gimmicks. In the end it will be all about the writing.

I'm planning to hold off for a while before using any more free days on my novels, as I think it has a deleterious effect to space them too proximately. I have a friend who found that out the hard way. My but says 10 weeks, minimum, between free promotions. That's only a hunch, but it feels right.

What happens after someone like an Apple makes a big push will be anyone's guess, though, so I'm a little cautious about signing up for another round and getting caught on a single platform. But we'll see.

Congrats on your sales, my friend. It's all good, as you know.