Is there such a thing as a shipper carrier partnership?

In good times, my conjecture is that there is…no such thing as a shipper carrier partnership.  Think about it, when they have a choice:
  • Do carriers accept a lower paying load from a favored “partner” shipper instead of a higher paying load from a “non-partner”?
  • Do carriers accept the first load they are tendered or wait for a “partner shipper” to tender their loads?
  • Do shippers wait for a “partner carrier’s” equipment to be available when there is a load to ship?
 
As evidence:
  • The Wall Street Journal tells us:  “Heartland Express Inc., a large trucking company based in North Liberty, Iowa, has been turning down an average 10,000 loads a week from shippers like Walmart Inc. and Lowe’s Co’s”, surely companies with whom any carrier would like to partner.  As an aside, the article goes on to say “the turndown rate was about 500 loads a week at the start of 2017.”
  • When carriers have a dedicated arrangement with a shipper, they make higher margins.  (See JB Hunts annual financial statements)