I don't know why but I only saw the "physical products" part of your comment
For digital products I don't think there are many platforms with built-in traffic delivery... as a matter of fact I don't know any (aside from the ones you've mentioned).
The only option I can think of is advertising in ezines, but it can be very expensive. Have a look at DoE:
https://directoryofezines.com/
I paid $300 for this membership back in 2011 and I haven't used it once (because I ran out of money LOL). Back then it was the best source for solo ads advertising, but I can't vouch for it anymore. But if you have the money to test it I think you should give it a try... or just search for ezine directories in your niche (forex / crypto) and see what comes up.
the world is changing, man. The brainwashing and domination of the big tech companies (Google, Microsoft, Apple) over our minds is starting to wash off and people are not money spending drones like they used to be 10 years ago, at least that's the feeling I get lately and it might, or might not be true, I don't know...
But anyway, at least you're getting some sales, which is better than nothing...
try LinkedIn and Pinterest (although, I don't think your niches are suited for Pinterest), maybe they turn out to be hidden gems...
I hate saying it, but probably no
Although... if you have a lot of free time to waste and you're decently knowledgeable on forex / crypto you could try forum marketing. Find 2-3 big forums in these industries, join them, and start participating in discussions and providing valuable insights and when people see your site in your profile they might click on it and become your customers. This also means that you should probably look into email marketing because if you acquire customers slowly you want to get the most out of them and the best way of doing this is by getting them on your email list and do email marketing to them.
