You can put up banners on your site, to promote your affiliate offers. Most affiliate programs will usually provide their own creatives when you sign up for their offers. All you have to do is insert the banner on a highly trafficked page (your affiliate tracking is usually embedded within the code). Banner ads in the right locations can do a great job of driving sales.
Yes and no. Affiliate marketing can generate passive income, but the passive side of the income usually only follows putting in a few years of hard work to generate the brand and audience you'll need to begin generating those passive sales. I have multiple sites earning passive income, but each of those sites took a lot of front end work to build up to that point. And not every site gets to the point of passive income. Some sites require continual maintenance though the revenue they generate can also allow you to pay for that maintenance to be done vs. you needing to do it yourself.
Medium is an online community where anyone can post articles and essays and get them in front of their audience of millions of monthly readers. While it can be a great place to build your audience for your own blog or find customers for your consulting business, with Medium’s new Partner Program, you can now make money online whenever someone reads your articles. Register for free and you can choose whether your articles are freely available or only readable by those people paying $5/month for a premium Medium membership. You’ll make money based on the amount of people who read and engage with your posts each month.