Evidently it's not just us. This was posted on the Amazon Associate's forum this weekend, about sales through his/her website (the percentage figures refer to conversion of click-throughs to sales):
It can't be because of the holiday. I've experienced a precipitous drop in the last couple of days. I primarily deal with books and yesterday it looks like not a single Kindle book was sold. I was under 1% as well, when normally things are at least at 5%.
Something has seriously gone wrong with the reporting in the last couple of days.
Brown bar of shame is what I have too. I was so excited that a full month after my free promotions, I still had 50+ sales this past month. But come March 1, nothing. And one book was ranked 67,000 and it fell in to days over 200,000!??????
It seems to me that the first few days of a new month are kind of slow. Perhaps people are busy with paying bills and taking care of other business before settling back down to buy books. Just a guess.