1. Digital Marketing Specialization by Coursera: Offered by the University of Illinois at Urbana-Champaign, this specialization covers various aspects of digital marketing, including marketing analytics, social media, and SEO. It provides a comprehensive understanding of digital marketing strategies and techniques.

1. Marketing in a Digital World by Coursera: Developed by the University of Illinois at Urbana-Champaign, this course explores how digital tools, such as social media and analytics, impact marketing. It focuses on developing a digital marketing strategy and leveraging digital platforms effectively.

1. Marketing Analytics by edX: This course, offered by the University of California, Berkeley, delves into the use of analytics in marketing decision-making. It covers concepts like customer lifetime value, segmentation, targeting, and positioning, and teaches how to make data-driven marketing decisions.

1. Social Media Marketing Specialization by Coursera: This specialization, offered by Northwestern University, provides a comprehensive understanding of social media marketing strategies and techniques. It covers topics like content creation, influencer marketing, and social media analytics.

1. Strategic Social Media Marketing by edX: Developed by Boston University, this course focuses on creating a social media marketing plan and leveraging social media platforms to achieve marketing goals. It explores various aspects of social media marketing, including advertising, analytics, and engagement strategies.

These are just a few examples, and there are numerous other online courses available that can help MBA graduates enhance their marketing skills. When choosing a course, consider factors such as the course content, instructor expertise, user reviews, and the specific areas you want to develop expertise in.