That depends. Is the plaintiff's goal to encourage a business to comply or is it to get paid? If compliance was the goal, sending a letter would always be the first step.
But if a claimant does send a letter and that letter gets ignored, what's their recourse if they can't sue? Send another, more angrily worded letter? That will show the defiant business owner what for! They'd likely have to find someone else to do file suit.
I'm not a lawyer and I'm sure that article is simplifying things, but using the information given, I would also sue first.