A 'lurker' typically observes without joining online discussions or activities. Even though she logs in daily, she's more of a lurker in the chat room.
Pro Tip 2/3
Negative Implication
'Lurker' can suggest disapproval when someone is expected to participate but doesn't. Don't be a lurker; share your thoughts with the group!
Pro Tip 3/3
Neutral Observation
Sometimes 'lurker' just means observing quietly, without any negative feeling. As a lurker, she learned a lot from the online seminar.