Starting a podcast, like making a YouTube channel or blog, comes down to telling interesting stories and building an engaged audience. I’m probably sounding like a broken record by now, but you need a niche that you’re interested in and there’s already a demand for. Come up with a list of topics you’d like to talk about and then search iTunes charts, Google Trends and other podcast research sites like cast.market to see what’s currently out there and popular.
Get-rich-quick schemes and fad weight-loss diets are naturally popular because they satisfy the id while also attending to the super-ego. The ego's job is complete when it sees something like this. The appeal of "fast'' stems from the innate desire for instant gratification, so beware of what seems too good to be true (they often are) when you're looking to make money quickly. Be wary. Listen to the conversation deep within the confines of your mind and do your best to tame the proverbial beasts.