Huh, I never figured about using reblogs to archive stuff I like. Honestly, I've always seen Tumblr as very fleeting in nature, and so I've saved the stuff I really want to keep to my hard-drive. I only reblog if I think my followers will want to see the content, or I want them to see the content regardless of their own desires. XD That's why I've avoided public discussions, or held in them mainly via Replies, as I don't think my followers give two shakes about me debating or discussing content they're not engaged with.

I think you're the one doing it properly, as I have very few followers and less than 10 who actually make their voices known. But I'm satisfied enough with my experience.