The topic you choose must have enough depth that you can create a lot of content for it. This is important for building an authoritative site, for search engine optimization, and most importantly, for the end user. If you don't have enough content about a topic, you're not going to be taken very seriously as an authority on the topic and it's unlikely you can convince someone to make a purchase from you.
This has become a popular business model for online entrepreneurs over the past several years, and will probably just continue to grow in popularity. The best thing about selling online courses is that once you do the up-front work in creating the course and setting up your marketing strategy, you can get paid over and over again for work you do once.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
When was the last time you went to a new restaurant without looking it up online beforehand? Or bought a product that didn’t have at least a few 5-star reviews? It seems like more and more our world is run on reviews. And you can make money online by writing them. Get started by creating accounts on sites like Vindale research, Software Judge, FameBit, CrowdTap, Influence Central, and Modern Mom. However, before you run off and start writing, be sure to check the small print on each of these sites. Writing reviews isn’t a huge source of guaranteed income and you want to make sure that it’s worth your time before you get going.
Ever since the idea of online auctions came into existence, the online selling market has been on the rise. Many are interested, but don’t know how to get started. There are still all kinds of ways to make money by selling online, whether you’re selling what you already have or buying and selling like a store. Before we get started, here are a few general tips when selling anything online:
Very nice article! Affiliate marketing is perfect for bloggers as long as they offer quality content and are upfront about it. If people are willing to donate money to YouTubers via Patreon, why wouldn’t they buy something that they want or need through the site or blog of someone that offers them great content and support his or her efforts? It’s a win – win kind of deal.
If you have pop-ups and optins on every page, I would have to think that it would be a lot harder to convince someone to link to it. Especially since the pages where you have your optins (and probably receive the most traffic) are probably the same pages that you have your best content on as well that you'd be hoping to pitch in your outreach campaign.