So a month ago I wrote a big long blog entry about free eBooks where I said I’d be curious to see what the effect was on my books when Tor gave away Crystal Rain as part of their nifty new site promotion.

I can show you a graph without specific numbers and talk a little bit about it what I think I saw the eBook giveaway do to sales.

Ebookpriceaffect

There are two problems with my numbers. One, both Crystal Rain and Ragamuffin are well out of ‘on the shelf’ season for both books (Crystal Rain ppb out in May ’07, Ragamuffin hardcover June ’07), so the sales are dribbling in. With that in mind, it doesn’t take too much of a fluctuation to look dramatic. Someone with a larger weekly sales stream than me might not see something as dramatic.

The second problem was that with the nomination for the Nebula award and the Prometheus award were out there, I imagine press releases or notices about that may have had some effect on sales as well and slightly muddy the data (a good problem to have, though).

So the blue line is Crystal Rain sales. Two weeks before the free eBook giveaway it had spiked up, and four weeks before that it had also spiked up quite a bit suddenly, so at at the end of the chart we see a fourth spike during the week of the Tor giveaway. All throughout January, before the Nebula news, the Prometheus award news, and the free eBook giveaway, the book had been selling in area of the lowest part of that blue line’s dip. I’ll show you that later.

The biggest effect was on Ragamuffin, the yellow line, which had an unmistakeable jump, indicating that we can probably assume that since people read the first one, they seem to have ordered the second one… that yellow jump in sales is a 400% increase in sales.

The big picture on how these things worked is here. The sales line of January 1st through March 30th:

Longebooksales

This picture shows the story. Crystal Rain paperback sales steadily flowing through January with very low Ragamuffin sales, and in mid-January as the Nebula preliminary ballot comes out, a jump in sales. That’s thanks to both the ballot getting passed around, and I’ll be this Instapundit link right here (thank you Glenn Reynolds).

Both books taper off, until Crystal Rain grabs legs in early February and runs off. Why is this? I have no idea, maybe just my name being around the web more than normal. The right alignment of planets and starts. I’m not sure. Crystal Rain in paperback then slumps, but in late February/early March, thanks to the Nebula final ballot, it looks like both novels spike together.

After this Ragamuffin slides back down to level, but Crystal Rain keeps selling nicely. My theory for why this is is that Crystal Rain in paperback is more widely distributed in bookstores (anecdotally and from what people email me) than Ragamuffin in hardcover, which really didn’t get much in the way of bookshelf space.

However, on this graph, you can see that both Crystal Rain and Ragamuffin sales pick up quite nicely after the Tor eBook giveaway. On Wednesday I might update this graph, as I’m curious to see if the free eBook giveaway keeps that little surge going or not.

Certainly the giveaway does not seem to have negatively impacted sales, but rather, positively impacted sales, certainly of the sequel, which showed a distinct set of bumps at the time of the preliminary ballot and then the finalist, and then for the giveaway.

What I do find interesting is that giving away a book free seems to have had about the same impact on my novel’s sales as getting nominated for a major award in terms of direct sales.