I have now several times experienced recieving mails after publishing a preprint, from authors asking me to cite their work before I submit it to a journal. In some cases it is probably fair, but in other cases a bit of a stretch. It is of course often people I know, and who could possibly be future colleagues, so I don't want to be too snarky.
I have never done it myself. I have, however, approaced authors to refer them to my own work, after a related article had been published in a journal.
Do you have a standard reply for such solicitations?
Do you engage in this practice yourself? I imagine that it could do wonders to your citation count.