If you visit a thread multiple times the views will not be counted, only if you open it after a 10-15 period of inactivity after your session expires.
There's no time limit if you visit a separate thread: try it.
Check the view count on this thread right now, visit another thread, then come back. (It also increases on new replies)
Actions must be the viewing of "pseudo-new" threads, replies, and decay after some duration.
(but not edits nor private messages)