How does affiliate marketing differ from influencer marketing?

I think they overlap. Many influencers also use affiliate marketing links. For example, a YouTuber might get paid by a brand and include an affiliate link in the description. So the difference is blurred now.

Affiliate marketing is about promoting with a unique link and getting commission per sale. Influencer marketing is when a brand pays you upfront to promote to your audience. One is performance-based, the other is sponsorship-based.

Influencer marketing works more like advertising. Affiliate marketing is risk-free for the company because they only pay if a sale happens. With influencers, the company pays for exposure, not guaranteed sales.