The logistics of getting a large number of items on these sites are considerable and tend to limit your product line and therefore your profits. (entrepreneur.com)
He adds that retailers should not limit their product assortment to one or two items or to only cleaners and odor treatments that use just one of the different technologies on the market. (petbusiness.com)
For most designers and makers the reverse is actually true: limit your product range and / or your target market and you'll find it easier to grow your business. (blog.folksy.com)