Everyone has given lots of good advice, but here's a thought ---
why not search for "magic product", rather than magic # of listings? Case in point: my 1st Etsy shop (now closed by me) had lots of listings & ok pics & descriptions. I went one year with one sale! I closed it, and opened another shop, but only after having done a lot of market reasearch on what people were buying, within the area of my skills. My 2nd and then 3rd shops were opened, and, while I'm still learning, I'm doing much, much better.
What changed most? My product.