> And the whole platform is about conversation!

I always understood Twitter to be a personal text broadcasting service, i.e. single direction communication, not conversation.

Tumblr already has conversations that you can read, but only everything up to the specific post you found up to a point (you can look in the notes for the reply but it can get messy). Unlike a forum which consists of all the posts, each reblog chain contains each post previously. It also means if you follow both parties in an ongoing chain, each reply will occur in your feed in the reverse order of their posting.

i'm not a huge fan of the way twitter presents threads and conversations, but the few times i've tried to follow a conversation on tumblr i've only found it to be even worse than twitter. i'm not sure tumblr is the saviour we're looking for here.

You're right, but that these millions dollars startups aren't able to do better than phpBB from an UX point of view is dazzling.