I include affiliate links on my blog, which means I’ll earn a commission if you click on an affiliate link and then buy something through it. (There’s no extra charge to you, though.) If you do choose to buy through any of my affiliate links, thank you! I appreciate it.
For example, I’m a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. So if I mention a book or some other product sold on Amazon that I like, I’ll (usually) use an affiliate link to do so. I participate in a variety of other affiliate programs too.
It’s one way many bloggers (including me) make a little bit of money. (There are some more ideas for making money in my book if you’re interested.)