Persuade vs. convince
An anonymous copyeditor working on my new book unilaterally changed each usage of "persuade" to "convince."
I had to change them all back.
Marketers don't convince. Engineers convince. Marketers persuade. Persuasion appeals to the emotions and to fear and to the imagination. Convincing requires a spreadsheet or some other rational device.
It's much easier to persuade someone if they're already convinced, if they already know the facts. But it's impossible to change someone's mind merely by convincing them of your point.
If you're spending a lot of your time trying to convince people, it's no wonder it's not working.