It is a smart strategy to thank an interviewer so that the interviewer can keep remembering the candidate in future. This is because there will be high chances that the interviewer might keep the email of being thanked by the interviewee. Following up with the interviewer is important because the interviewer can consider the interviewee to be interested to work in the organization in the future. Therefore, there can be preference given to such a candidate by the interviewer in future. The interviewer can save money in advertising the vacancy available of similar candidates to work in the organization in future.