"A CEO with hotel chain A found himself having to spend a night in a hotel from hotel chain B. Naturally, he was very curious as to what kind of information systems they had, and resolved to keep an open eye for any competitive use of IT. As he approached the reception for first time, the woman behind it smiled at him and said "Welcome back, Sir".
he said 'But...it is 12 years since I was here last! How could you know
that I have stayed here before, what kind of advanced information
systems do you have that can store and find the fact that I was here 12
'Well, it is really very simple', she said.
'When the doorman opened the door to your cab, he asked if this was
your first stay with us. You answered no, and as you walked through the
door, the doorman looked at me through the window and touched his nose.
That told me that you should be welcomed back....'"