You know, sometimes Indieweb people say "this is a case for webmentions!" when I'm... not really sure it's a case for webmentions. But this?
This is 100% a case for webmentions.
When I post something on my website, brid.gy syncs it over to Mastodon as well. Then when someone responds, that gets formatted as a webmention, as here. But if someone wants, they can use a webmention to put their reply to something right on their own site (hi matt hope it's okay to use this as an example). The webmention acts as a programmatic notification about it, so I can decide whether or not to link/excerpt on my page and my webmention software handles the paperwork. It's like
[authoring] your own post and [emailing] her to notify her of your thoughts, giving her the ability to add a link to the follow-up discussion.
but made easy.