Hi Hector!
Was just researching to see if this was possible as it’d be great for a Mailchimp RSS-driven campaign.
Will the update use post_meta to store a post’s popularity in some way?
You may well be aware but the WordPress RSS feed can be filtered with URL parameters, e.g:
/feed/?orderby=meta_value&order=ASC&meta_key=_edit_last
So once posts have the necessary metadata, the RSS feed more or less takes care of itself.
Apologies if you already know this / if it’s what you’re working on! 🙂