After completing a full day of interviews, a common question I receive from my candidates is whether they should send a thank you note to each of their interviewers. There are two different schools of thought on this question, and I believe that there is no right answer. Instead, I believe each candidate should do what makes him/her most comfortable. While some believe that a thank you note is absolutely necessary, I believe sending a thank you note could actually hurt your candidacy if it is not done correctly. In my personal experience as a member of the hiring committee at my old firm and a frequent interviewer of lateral candidates, a thank you note never changed my mind regarding a potential candidate. My decision was always based upon my personal interaction with a candidate. At most, a well-written thank you note from a candidate whom I had liked simply reaffirmed my positive impression. However, it never changed a "no" decision to a "yes" decision. Thus, I do not believe that thank you notes are absolutely necessary. However, I am sure that there are many people who would disagree with me. So, if you are going to send a thank you note, there are several important rules you must follow.
First and most important, make sure that there are no typographical or grammatical errors in your thank you note. If necessary, have someone else (like your recruiter) read your thank you note to make sure that it does not contain any embarrassing mistakes. This is your last impression with an interviewer, and you want to make sure that you do make the most of it. For example, one of my colleague's candidates met with two different firms on the same day, and was in a rush to send out his thank you notes when he got home that evening. Thus, he typed out a simple, generic note and "cut and paste" the same thank you note to each interviewer. Unfortunately, he forgot to change the name of the firm. Needless to say, this made a bad impression on the firm and the candidate did not get the job offer. It is impossible to say whether this one mistake was the reason for the firm's decision, but it certainly did not help.
Second, do not send the same thank you note to each interviewer. Make every attempt to personalize your thank you note in some way. After all, interviewers have been known to compare notes and you do not want your last attempt to leave a positive impression to seem false in any way.
Third, send your thank you note in a timely manner. The purpose of your thank you note is to help solidify the hopefully positive impression that you made. Typically, an interviewer completes an evaluation shortly after meeting with a candidate, and you want to make sure that your thank you note reaches the interviewer before that evaluation is completed.
Fourth, keep the thank you note short and sweet. Do not use the thank you note as a means to repeat all of your qualifications and reasons why you believe you would be a perfect fit for the job. Hopefully you will have already covered this during your interview as well as in your resume and your cover letter.
Lastly, the second most common question I receive after whether to send a thank you note at all is whether to send a handwritten thank you note or whether an email is sufficient. I believe that either method is fine. There are pros and cons to each approach which will depend on both the candidate and the interviewer. For example, if your handwriting is hard to read or you do not have the ability to use formal stationery, you may opt to send an email. An email will also be certain to reach the interviewer in a timely manner. On the other hand, some interviewers may prefer the traditional approach of handwritten thank you notes, which unfortunately is impossible to determine. Also, a well-done handwritten thank you note can win you style points. At the end of the day, either method is fine.