Other methods to promote affiliate products [besides email marketing] are:
Content Marketing [Blogging or Vlogging optimized with SEO]
Private social media groups and communities [you are the admin]
Private instant messenger groups [you are the admin].
Self-owned website.
Paid social media ads.
Trusted solo ads networks.
Cross-promotion with other affiliates or businesses.
Through Podcasts.
Here's related information that you may find helpful – 37 Hard Secrets Every Beginner or Intermediate Affiliate Marketer Need To Be Aware Of.
P.S:
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