Constant Content

I haven't sold an article for over two months (until today, that is). My sales were healthy until November, and then they fell off a cliff (then again, I only have about 25 articles up). Is tis kind of sales variance normal? I was thinking that sales might have dropped across the site due to people spending money on Christmas presents rather than website articles. Has anyone else noticed a drop-off in sales?

My sales fell off in November and December. In December I sold only one $10 article. When I woke up this monring, however, I was pleasantly surprised to see one of my usage articles (written months ago) had sold for the second time. I am blaming the holidays for the slow sales, but then I also haven't submitted as much as I had been over the preceding months. I plan to step up my submissions this month and see what happens