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.
If you're serious about making money online, start a blog. Blogging is one of the easiest and most sustainable income sources. As long as the blog is setup the right way, in the right niche, with the right content targeted at the right audience, and the offer is complementary to the content, you could make a tremendous amount of passive income from a blog.
Free traffic, such as organic search engine visitors, video marketing, or social media/forum traffic, can be a great way to get highly relevant visitors to your website without paying for each visitor. Building a platform that delivers free traffic can be a great long-term affiliate marketing strategy. However, the downsides of free traffic are that it can take a lot of time and effort before you start seeing results, and can be unreliable.