I learned this the hard way last year when I launched a new blog… it felt icky doing it but I convinced myself that it was part of growing and “getting outside my comfort zone”. I was promoting something I believed in, but it was too heavy handed because my focus was more on making money than serving my audience. I got my first unsubscribers that week… lesson learned. Not that I’ve sworn off selling, but I’m learning how to do it in a way that doesn’t turn people off.
Notice that I avoided putting a specific dollar figure on the amount you can make from blogging. It will come down to your work ethic, your skills as a writer, your ability to generate targeted traffic, and plain old good luck. It’s a bit like baseball: everyone played it as a kid, only a small fraction make it to college ball, an even smaller number become professional, but only the cream of the crop makes it to the majors.
Have in-depth knowledge in your niche? Package it up into an ebook and sell it on your blog. I'd generally advise against selling it (at least exclusively) on Amazon or Kobo, as you'll probably be able to charge much less. If you've already built up a solid audience, you can probably change anywhere from $5 for a very short one, all the way up to $39+.
Write content. I like to write an article from beginning to end with no breaks. It may take me an hour to write an article or I may be at it all day. Sometimes, content does span a few days, but for the most part, I like to finish a piece of content in one sitting. I then hand over the content to my editor to fix anything from grammar, punctuation, to the general flow of the article. The only thing she doesn't edit is my monthly income report.