Dude, I'll give a pass to trying to increase traffic to your Youtube channel; I have no qualms with that. If you feel that you're sharing a tactic that most people don't know about, I'll give you a pass on that even if you're wrong in the assumption that it's unknown; that certainly wouldn't qualify as spam.
BUT...
the assumption that most people don't know about this, as well as the statement that the information isn't readily available, is ludicrous. Whether or not it is in the War Academy is irrelevant to the point, the fact is that when you click on any trade route, caravans and cargoships alike, it lists the internal trade routes BEFORE listing the external trade routes--- meaning that you need to intentionally scroll past the internals to see the externals; it's impossible to see external TR options without first noting the internal ones. As such, your post would make more sense if you mentioned the complete opposite as a "trick"; there's an infinitesimal possibility that someone doesn't know about external TRs generating gold and beakers because they never actually scrolled past the food and hammer options.
As a civ5 veteran, I found the thread a little annoying, as I thought there might be some new tactic that I haven't already folded into my strategy. Instead, it was akin to someone patenting common sense.
Still, I'll give you props for coming up with the idea of generating traffic to your Youtube channel; it's original. This may or may not be because it's in violation of forum rules, kind if a gray area and not for me to decide. It does come off as extremely underhanded that the tactic referred to cannot be obtained without following the link. By saying it here and showing it there instead of giving nothing here and forcing the reader to follow the link, you'd probably generate slightly less traffic but would seem much less deceitful in doing so. More importantly, you need to do the work to earn that paycheck- spend some time in the game and try different, unconventional things and find something that actually isn't common knowledge and works well. That way you'd actually have your own "trick" instead of stamping your personal trademark on the obvious.