Liz Strauss said it better than I ever could.
In summary, publishing is a business. Even if you self-publish, you’ve got to impress your editor and your publisher with a product that can sell. Do your editor and publisher have the skills to know what readers will buy?
The hard part is the marketing. If you aren’t prepared to handle the marketing part of your book, even a self-published poetry book, then you shouldn’t be publishing. It’s your money, but publishing a book without intent to earn a profit on it just because you think it’s good is sheer vanity. Throwing a blog up with all of your poems on it as a free buffet isn’t publishing. It’s giving away your rare jewels (if the poetry is any good). If it isn’t any good then you’re just giving away pebble stones.
An author thinks about creation. An editor thinks about packaging. A publisher thinks about marketing. You’d better be able to do all three or you’ll never survive.