Take two decent, similar products from two decent companies.
Give one a set of instructions that are well-written, clear, and easy to follow.
Guaranteed — all the word of mouth goes to the company with the better instructions. “Buy from Staples. Their stuff is so much easier to assemble.”
Making customers happy is always good, but this is also a critical differentiation strategy when any competitor can copy anything you produce. Build a brand around the instructions instead of the product.
Here are the instructions from a Staples office chair – click for close-ups. My 6-year-old was able to build it (but he’s a genius, of course).