How to catch up with a lot of targeted traffic with minimal cost?

Question

contextual advertising

Given:
A) a landing page with a free product
B) a sales funnel based on a series of auto-mails leading the user through the sales funnel.
1. Newsletter subscription
2. Free products
3. Inexpensive products
4. Expensive products
-. promotional products.
6. endless repetition from point 2 to point -
Task:
find channels to attract targeted traffic.
contextual advertising disappears (you cannot target segments and audiences according to the placement rules. everywhere).
PS yes, the question is banal. yes, googled. nevertheless, they told me that there are cool specialists here, so I will listen to the pros. THX )