On thing that helps is I have a whole page on my list website.

Does't stop the people that have become immune to seeing the banner, but it
helps.  That and a quick reminder if needed.

The webpage has clickable links, for the browsers that support that.

I do have to give an award for self searching and solving to a particular
subscriber I had.  Two and a half years after migrating from a majordomo
listserv, this subscriber wrote the list and proudly announced how she had
finally discovered why she couldn't unsubscribe from the list, how the list
had moved, and the correct instructions to unsubscribe from the list should
anybody desire to do so.

Perhaps finally noticed the banner?

Randy