Common courtesy and politeness go far in interviewing; thus, the importance of thanking each person who interviews you should come as no surprise. Start the process while at the interview, thanking each person who interviewed you before you leave.
Also, write a thank-you email or note shortly after the interview. The thank you emails will not get you the job offer, but doing so will certainly give you an edge over any of the other finalists who didn’t bother to send thank-you notes.
This thank you note or email thing, does it work? Or is just simply curtsy