Publishing and promoting go hand in hand, and when you are ready, a strategy of promoting your work makes sense since it helps to move readers to your books or blogs.
If you believe your work is worth paying for then you can submit it to journals and magazines appropriate for your genre. And, if they feel the same way about your work, then they'll buy 1st year publication rights from you and promote it. You get money and exposure.
They usually don't provide feedback, though. Just a form rejection note. I've collected 40 something so far.
So if you want readers to provide you meaningful feedback on your pieces, then sites like [Reddit Writing] 1 and [Scribophile] 2 might be more appropriate. There are lots and lots of sites, many genre specific, that you can share your work with other writers. The expectation is that you will return the favor by critiquing other works on those sites as a way of paying it forward.
It is very important to remember that the quality of the critique is usually proportional to how much you pay. Most sites on the intergalactic interweb are free -- other than the effort to critique other's work. The quality of the feedback, since it is often by people still learning to be writers, varies tremendously. You can expect anything from a no effort 'I liked it' to mocking savagery because your authorial voice dared tread on one of that author's personal bugbears.
If you want valuable feedback, then one place is from the great number of online creative writing programs offered by universities and published authors. These are always for pay, but the quality of feedback on your writing is almost always top drawer.