Don’t get me wrong – exclusivity can be a wonderful thing. If you’re getting something in return. Consider this situation:

You sell breakfast cereal. Some of your products are at the budget end of the scale, others more premium. Your net wholesale profit per unit is around $2 – $4, depending on the product range in question. You sell to Walmart, who represent about 85% of your sales, and a bunch of other supermarkets who make up the other 15%. Things are looking pretty good.

One day, Walmart ca...