Founders who are seeking extra income and/or visibility can efficiently do that by productizing their knowledge. This is also a forcing function to think about key learnings and crystalize them. Specifically, you can: 

• Convert your expertise into a course or an ebook. Adham Abdelfattah said, “I believe Gumroad and Teachable are the best, since they have low fees and allow the creator to own their audience relationship. The trade-off is doing your own marketing which can be time-consuming, but in itself is a learning experience. Udemy offers a platform with organic traffic, but the trade-off is you do not own your audience relationship. My recommendation there is for the founder to focus on a topic they know well, cap the investment at a week or two of time, and publish something simple and unpolished. Example: I have personally found decent success so far with a course summarizing the consulting problem-solving method which has 381 students in 44 countries so far. Another very successful example is Daniel Vassalo, who left Amazon to start a new business and is funding himself through info products.”
• Create a newsletter. Adham continues, “One can opt for an off the shelf solution like Substack, or a combination of Ghost (has an entire membership + newsletter stack). A great example of a newsletter writer in transition who succeeded is the story of Lenny’s (former Airbnb PM) Newsletter and he laid out his process here. Newsletters are also very useful for recruiting if the founder wants a job. They’re a resume with natural filters. For example, I just had an A16Z & Marc Benioff funded startup ask me to join as their CPO/COO after their founder read my newsletter. Of course, we had a lot of conversations too, but the discovery came through the newsletter.”