Across all industries, routes to market are consolidating.  This means that most suppliers make the vast majority of their sales to a few big distributors or retailers.  Often this "lion's share" group makes up 80% or more of sales in any given channel.
 
So how well a supplier manages these companies really is the key to its own profitability.
 
In practice, most suppliers measure product profitability, but struggle to track the margins they make from their partners. When they do, they usually find that the lion's share companies deliver over 100% of their profit - in other words, the rest of their partners lose them money.  But even this fact hides the real insight...

Typically, I find that the best lion's share partners are generating margins that are 30% or 40% higher for their suppliers than the worst.  On sales of hundreds of millions of dollars that is a huge difference.

And this exercise is not just about profit margin.  Roll up your sleeves and get right down to granular detail.  What about the cost to serve each lion's share company?  Some demand vast slabs of account management time. What assets are you deploying to support the relationship?  Some partners want you to ship inventory to a thousand outlets.  And how do these costs vary from one national arm to another?

Unless you have done this exercise, you really can't develop any serious partner strategy.  You will simply be subsidising your worst customers at the expense of the best. And, in today's tight markets, that can be the difference between success and failure.