No sales for a week

I have a portfolio of 2500 pictures and sell at least every other day, often even one or more pictures every day. I also upload pictures regularly, so I am active. At least once a week.
Now I haven't had a sale since 14 November. Can this be normal? I'm not blocked or anything. I was taken over by Fotolia, so I've been there from the start.

Grüße

Jürgen