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.
Creating space for banner ads on your website is another way to generate a revenue from adverts. However for this type of advertising you will need to contact businesses directly and ask them if they would like to advertise on your website. The upside is that you can charge a set amount, or even a recurring monthly fee, to business to promote their services on your site. Using a WordPress plugin like AdSanity is an effective way to manage this type of advertising.
A popular tactic to make money on social media is to pay for advertising affiliate products. Create ads for particular affiliate products that are big sellers and have a high yield. Then target these ads at specific custom audiences to ensure your ads are viewed by those who will have an interest in the product you are promoting. If viewers click through your from advert to the product page and make a purchase then you will earn an affiliate fee.
Here’s a good example of how lead sales can work in real life: My second website, Life Insurance by Jeff, brings in a ton of traffic from people who are searching the web to find answers to life insurance questions. While I used to have the website set up so I could sell these people life insurance myself, it was a lot of work to process all the different requests and clients. As a result, I started selling the leads I gathered instead.