One of the best (and only) pieces of advice given to me by another writer about the book promo that we all have to do (an unfortunate necessity) was: put the buy links in your promotional posts.
This seems obvious but a lot of authors (including me, still, to this day) forget to do this, or don't want to seem pushy, or assume that anyone interested can look up the title/author and find it to buy it.
But what this author told me, and which I know is true because I have done it myself, is that a lot of people will see your promo posts and they will be interested--but life is chaotic and the internet is full of distractions and they can forget. Easily. They can open it up in a new tab that is one of a million open tabs they have. They do like I do and bookmark it to look at later--forgetting the absolute mess of a bookmark collection they already have. (No joke, my bookmarks are Bertie's library before Arthur). They can even go to the booksellers' websites and get distracted there--because those websites are designed to sell sell sell! and that doesn't mean your book, it means anything.
So you make it as easy as possible for readers to go look at your work and maybe buy some of it, and you include links to help them.
Which is an attitude that helped me (somewhat) with the "this feels pushy" impulse. You aren't forcing them to do anything, but the link will help them if they are interested.
Anyway. Honestly, as I said, most of the other DSP authors didn't give a shit about me and then apparently didn't like me, so the advice I've gotten from other authors is mostly outside of the m/m romance author world. But this advice is good and so I like to pass it on. :)