~ poker is one of those things that become obsolete after some time. Not very quickly, same strategies can work for years, but still after 10-15 years they may stop working. This applies to online poker first of all. You can use some ancient poker strategy playing in your neighborhood, and it will be working forever if your opponents don't use the internet to update their knowledge.
Does that suggest that the "Poker Courses" that OP is selling might be obsolete? Because why would those "masters" share their secrets, unless they can make more money from selling them than actually using them? It's probably just the same with those unprofitable traders who sell subscriptions to teach plebs how to be "day-traders".
likely that this is the case here. I'm not trying to say that OP is a cheater or something, but I personally wouldn't recommend to anyone to buy his courses. It's not even about the money you'll spend on them. It's about your head littering with outdated information.