Hm! I will generally always tag back, unless I get hit with something that I have no idea how to respond to - in which case it is (usually) hunt-the-mun-up-on-AIM-time. I'm pretty terrible at tagging out, both due to time constraints and comfort zones/writerly paranoia/etc., but in terms of posts I will or won't tag, familiarity with the canon is a plus, but not a must - particularly if the post/character seems interesting enough. The only thing that might make me wary is - well, something kind of similar to what Pho was saying about Sylar being able to get a 'read' on people. There are certain kinds of supernatural/occult/whatever characters with whom I'd prefer to have a rough idea of how Crowley's demonic...ness will interface, so I'm not going in blind. Then again, sometimes that's what's interesting. ;D

(Also, make that a belated 'yea' from me as well re: daily entertainment tag.)