I think codeforces should add notification option . Because suppose i commented on a blog 2 month ago , nobody replied my comment on that time . After 1 month 1 people answered my comment , and suppose this comment was effective and helpful for others . I forgot about that blog and topic which i commented so i didn't again visit that blog .[ But since there has no notification option so i didn't get such that " user replied to your comment on users blog " . ]
If there was a notification option a can be notified about that blog when someone commented .or reply my comment .