Much like this, I have developed my own superstitions when it comes to my Etsy shop. The most obvious two are the following.
There will be no new sales till all old ones are shipped
Every now and again I get a back load of custom orders, or a couple of days with many sales. Until I go to the post office and am then able to check all of my "shipped" boxes, there will be no incoming sales.
No items are ever sold while on sale
From time to time I get discouraged of selling something and opt to have a sale. No matter if it is a buy one get one 50% sale, free shipping (never ever offer free shipping, that is the worst decision an online seller can make) , discount, whatever - no one never buys anything on sale. I even had a few incidents when people bought an item that was on sale the day after the sale ended.
My recent large custom order. Nothing sold since I had them made.
Thank God I finally shipped them the other day, hopefully I will get some sales now.
Do you have any Etsy superstitions? Please share them here if you do.