I only have a few minutes to write this right now but I want to get something out there because someone asked me. I might expand it later.
If you’re a programmer and you want to earn some “passive income”, here’s my advice:
Write an e-book. Make that your first business, a business that sells an e-book.
For the e-book topic, find something that lies at the intersection of “narrow enough that I can be the dominant voice on the internet on this topic” and “popular enough that I can actually make a living selling things related to this topic”. I think Angular + Rails is a good example of a combination that lies at this intersection. The best situation is when there’s a lot of demand for information on the topic but not a lot of existing information fulfilling that demand. This was the case with Angular + Rails when I stepped in.
Before you write the book, register an SEO-friendly domain name (like angularonrails.com) and start writing blog posts there. Write posts that are a) incredibly specific, b) target toward something you believe people are googling for (e.g. “angular rails heroku”) and c) long and definitive. Use WordPress for your blog. I HATE WordPress but it really is the best tool for the job. Use WP Engine to host your WordPress blog.
As part of your site setup, register a Drip account, set up an opt-in form in Drip, then drop that form into your WordPress site so that you get an opt-in form on every page. Offer a lead magnet that you’ll give people in exchange for giving you their email address. Call it your “Free Guide to Getting Started with “.
Once you have a few hundred people on your list, use Gumroad and a Jeff Walker-style launch to pre-sell your e-book. Sell it for $49. Offer to deliver it in two months. If enough people buy (for me, “enough” was just seven people), write the book and deliver it. Do another Jeff Walker-style launch when the book is done.
If your launch goes well, turn your book into a video series and then launch that (again, Jeff Walker-style). Sell the video product for $99.
What comes next? I don’t know. I’ve gone through the preceding steps myself and I’ve made an average of a little over $700/mo for the first 9 months that I’ve made money on my e-book and video package. I can’t tell you what to do next because I myself haven’t done the next thing yet. My plan at this point is to focus on traffic and keep cranking up traffic until I get a sign that I should chance focus to something else.