Sure, here are 20 potential topics that could be covered in a Digital Media Strategy for E-Commerce course:

1. Introduction to digital media strategy for e-commerce.
2. Understanding the digital landscape for e-commerce.
3. Developing a digital marketing strategy for e-commerce.
4. Creating a customer persona and targeting them with digital media.
5. Keyword research and SEO strategy for e-commerce.
6. Creating a content strategy for e-commerce.
7. Social media strategy for e-commerce.
8. Developing a PPC (pay-per-click) strategy for e-commerce.
9. Email marketing strategy for e-commerce.
10. Retargeting strategy for e-commerce.
11. Affiliate marketing strategy for e-commerce.
12. Influencer marketing strategy for e-commerce.
13. Creating a landing page strategy for e-commerce.
14. Conversion rate optimization for e-commerce.
15. Understanding Google Analytics and measuring success.
16. E-commerce analytics and tracking.
17. Customer retention strategies for e-commerce.
18. Customer service and support for e-commerce.
19. Legal considerations for e-commerce marketing.
20. Emerging trends and best practices in digital media strategy for e-commerce.

These are just a few potential topics that could be covered in a Digital Media Strategy for E-Commerce course. The actual curriculum and content may vary based on the instructor, institution, and student needs.