One great way to generate a passive income is through affiliate marketing. Now, this does depend on the size of your list. Yes, size matters when it comes to your list. Especially if you're looking to make some serious money and do it on autopilot. But, list-building takes time. It doesn't happen overnight. And you need to add value to your list or you become obsolete.
Keep in touch your contacts from time to time and keep them updated. Also, with an email marketing campaign, you are branding yourself and creating authority as well. If you take care of email list, this will add so much value to your blog. If you need, offer some free advice to improve your scope.  A free product now and then will also help maintain interest and drive retention.  Building relationships with email marketing is a huge way to gain trust and long-term customers!
Residual income is the best model for money generation. Once you master and build up one avenue, you can devote your time and money into another avenue. Eventually you start reaping the benefits of multiple residual income avenues. Enabling you to have complete financial and time freedom. I recommend to all people to build these types of asset models as they can greatly improve their life.

Residual income is when you continue to get paid after the work is done. This includes royalties from books, movies, or songs and also income that comes from real estate or business investments where you don’t actually have to be present to earn it. For example, Bill Gates is still making a residual income from Microsoft even though he isn’t working there anymore.