While adding my WordPress plugin to the WordPress directory i had to add a readme text file with which the details of it end up on the WordPress site. One of the fields i had to enter was the Donate section.
I found it quite odd that it had it set up as a required field. I have seen many Developers add donate buttons to their site but i never considered it myself. As not to break the trend i have added donate button on the WordPress plugin page on this site, feel free to donate