Nick Campbell of ShakeItPhoto fame noted:
So, I updated my AppViz software when I got home today and surprisingly, I saw a big bump in my ShakeItPhoto sales on Christmas day. This got me thinking about what would cause such a spike. What would cause my sales to practically double going into Christmas?
And here's the video he made on the subject:
Also check out the actual blog post as it has quite a few details, including a graph.