Follow-up letters are usually sent for two reasons: first, follow-up letters serve as an opportunity for additional contact after an initial meeting, career fair, or networking meeting; second, follow-up letters can effectively revive a job search by reconnecting a contact with whom you have not spoken in a while.
Follow-up letters are different than thank you letters. The purpose of thank you letters is to thank someone for meeting with you and to reaffirm your interest in the position or industry at hand. Thank you letters are, in turn, sent immediately. A follow-up letter is sent several weeks after sending a thank you letter in order to touch base once again with your contact and to reintroduce yourself. A follow-up letter provides you with the opportunity to restate your interest and to check for new job leads or information. Another type of follow-up letter may be sent after submitting your resume and cover letter. If after several weeks, you have not heard from the employer, you should send a follow-up letter to reemphasize your interest in the company and the position