Accepting sponsored posts on your site is a common tactic to make money online. It helps your sponsors to get exposure by publishing a paid post. You can publish it once in a while to make some extra income from your blog.
When publishing a sponsored article, make sure to explicitly tell your audience that it is a sponsored one. Otherwise, the article might come off as a little out of sync to your trusting audience.
Another form of paid posting is when someone else pays you to post on their behalf. For example, Instagram influencers are often paid to promote brands to their sizable following. You can accept payment for these posts directly through your website, complete with a request form set at any price you want.