Yeah. There are multiple courses that teach free traffic. But I always advise people to try a real traffic strategy. How? YouTube is a goldmine traffic source where you present your best strategies. Guest posting is a great way to drive real visitors and subscribers to your mailing list.
Remember traffic is mo more problem, if you focus on driving so much value.
Free traffic can be generated but it involves a lot of work. If you think, you can achieve free traffic by just installing the bots then that is not what it is about. It involves a lot of techniques, skills, and learning to get your targetted traffic from these free bots.
I agree - it's not free traffic - it's earned traffic, earned with your time by writing, posting - sharing etc.
There is a saying: "free cheese is only in the mouse trap" - in this case, you get what you pay or don't pay. Free traffic is not free as it requires a lot of your time and effort. It's always good to explore both avenues, they might compliment each other well rather than just focusing on one and one only.