I ran a great toy store for 13 years. We would regularly win "Best Toy Store" Awards and we had an extremely loyal customer base.
I had a big belief that to be successful in the marketplace I was in, that I needed to have a strong school supply business in conjunction. The thinking at the time was to help our business have sales for most of the twelve months, rather than just fourth quarter.
I had every color and size of construction paper, hundreds of gallons of tempera paints, huge pieces of school furniture, not to mention all the other hundreds of items that a pre-school classroom would need.
I opened up a warehouse. I hired dedicated staff to process and ship orders. I eventually produced my own catalog. During this time, my small toy store kept getting bigger and better. However, my focus was on daycare centers and pre-school programs. I thought that's where my success would come from.
I started to import direct from Europe and I did a big run of product catalogs to try to cover 20 states, not just the state I was in (Massachusetts). My expenses exponentially were greatly exceeding my sales on the school/supply side of the business. Still I trudged on.
This is not a story to advise you to stay away from school/supplies. (It could easily be substituted in this story with clothing, candy, sporting goods, etc.) It's a story that I had a great toy store that did not receive my full focus, and that I drained money away from.
Follow where your business is telling you where to go. I had a great toy store, and a mediocre school/supply business, yet I spent 75% of my time(and most of my money), on the mediocre business.