Inventory Effects

Photo from here

Today We're continuing our discussions on inventory and sales for your store front.  If you're a regular on the Etsy message boards, you've seen the discussions about the volume of inventory and it's effects on sales, visibility, and numerous other aspects of your online store front.  Being an engineer by education, I'm always curious if this really has some weight to it or if there were other factors at play that allowed these shops to really take off. 

I realize it is hard to see firm numbers on the topic and I've read that anywhere from 20 - 150 listings is your target, but that's a lot of product and that's a large spread, therefore variable to really understand what kind of inventory you need to have in order to be successful. 

I don't expect you my readers to be able to answer this question succinctly, but for those of you who have been around longer than Stitch Silly, at what point did you really start to see an uptick?  Perhaps a poll is in order!  You know I love me a good math analysis problem! 

Bring on the numbers for me people!