"The authors take the position that persuasion is a science, not art, hence with the right approach anybody can become the master in the skill of persuasion."
My approach is a bit simpler than 50 tactics. My two favorite forms of persuasion are to be honest, and be correct. Maybe it's obvious I'm not in marketing.
The closest thing in the text to "be honest" was "Admitting you’re wrong makes people more trustworthy."
I didn't read the article carefully - maybe the book is a good read.