Feedbin does this! (Though not with as much cleverness as your suggestion.) https://feedbin.com/blog/2016/02/03/subscribe-to-email-newsletters-in-feedbin/ http

Feedbin does this! (Though not with as much cleverness as your suggestion.) https://feedbin.com/blog/2016/02/03/subscribe-to-email-newsletters-in-feedbin/ https://feedbin.com/blog/2016/02/03/subscribe-to-email-newsl... "You can now receive email newsletters in Feedbin."