The advice here has been so great I had to bookmark this thread!
Besides having a well selection of colors and patterns, you'll want to make sure to have various sized prints ranging from small to medium to large. Start checking out other quilt stores, both physically and those online, and see what you really like about them and what seems to be popular. You can quickly spot trends and which things have been around forever. (Tried & True) I am always amazed when my local quilt stores don't have things like a quarter inch foot or tools that should be common for any quilter's workbench like a seam ripper. Duh! (Workbench = sewing table, cutting table, et cetera)
Another thing you might consider if you set up a business is becoming a rep for one of the sewing machine manufacturers, like Bernina or Janome or Elna. Quilters are very loyal to their machine brand and being a rep will bring in a lot of business, as well as giving you a chance to use all the newly released models they come out with. Doesn't that just sound wonderful! (Can you tell where my agenda would be at?) :lol:
Nana2, I think you are likely right about people not going in because her color selection isn't very large, but I also think you are missing out on an opportunity. Sometimes those dull colors are perfect for blenders or to use as backings. You can pick up fabric for charity, for your Secret Sister, or as gifts. :wink: