You are at a restaurant and want to order. The waiter comes to your table to take the order, but instead of standing upright and jotting down the order he/she grabs a chair and sit down, or crouches down. Why does it happen?

To make more money
They work for tips and by doing
this they think they are breaking down the wall between you, the customer, and she/he, the waiter.

Apparantly by "being at the same level" (literally!) as the customer it should make the customer fork out more tips. Other things you may be a victim of is getting feeled up by the waiter (a gentle touch on the shoulder) or obsessive eye contact. By "befriending" you in the process they hope that you will be more generous than if the waiter simply did the job.