Sales have been fairly steady for me lately (knock wood). I haven't sold anything today yet, but I sold 20 cards yesterday, 28 on Monday, 25 on Sunday, 51 on Saturday, 44 on Friday, 43 last Thursday, and 23 last Wednesday.
I did have a lot of cards hit my account recently, and I recently changed my price structure. Previously, I had higher asking prices but I would accept all offers. Now, I lowered the asking price and counter some offers. Since I made that change, sales have been fairly brisk.
It should be noted that I have about 15 times as many cards listed as you, so proportionately, my sales would be the equivalent of you selling 1-3 cards per day. If you sell 0 cards on one day, it would be difficult to read anything statistically significant into that.
My general sense is that the cards which sell the best are cards which people need to complete sets, cards of the collector's favorite players / teams, and cards being sold at an extreme discount to guide. Hope that helps. Good luck!