Participate in royalty-based venture financing. In traditional venture financing, an investor buys a stake in a company to provide growth capital to its founders. This investor is then entitled to a percentage of the gains experienced when a company is bought or has an initial public offering. However, there is another kind of venture financing where an investor can invest start-up capital in exchange for regular royalty payments that are based on the company's revenue. This doesn't give the investor any ownership in the company, but does guarantee regular payouts (assuming the company survives).

Certain posts that you create can work like passive income for you.  For example, if you have display advertising on your blog, then this is purely passive income, though you do need to keep creating content for returning visitors and subscribers.  It takes a long time before you can monetize a blog, at least 6 months.  This is why a lot of people drop out of blogging before 6 months, because it is a lot of hard work.

I had to get out. I actually had this random Facebook ad come up in my news feed (go figure) and it eventually led me to a webinar that taught on how to start an email marketing business (which is, by the way, the most profitable form of affiliate marketing – or ANY marketing for that matter). I listened through the whole 2 hours, completely mesmerized. By the end of it, I knew what I was going to be focusing on to help my family out of the pit of debt we were in and into a world free of financial stress. I didn’t know if it would actually work, but eventually it lead to EXCESS income!
Wealthsimple is the largest robo-advisor company in Canada, and it has over $1.9 billion assets under management.  It is backed by Power Financial Corporation and was created right here in Canada (Toronto), thanks to the founder and CEO of Wealthsimple, Michael Katchen (who was only 29 years old when he got $37 million in funding from Power Financial to start up Wealthsimple).
Build a list in a particular niche and tell them stories. Create a bond. Build a relationship with them. It's important. Then, when you've created a bit of culture, start marketing affiliate products or services to them that you think they might like. Just be sure that you personally vet out whatever it is that you're selling to avoid complaints if the product or service falls short.

How much money do I need to invest to make 3000 a month?