It is strongly recommended that you send a thank you letter, note, card, or e-mail after an interview to thank the recruiters for their time and consideration.  Following-up is the "golden key" to getting hired.  It shows that you are truly interested in the position, that you have a positive attitude, and that you can take the initiative.

 

Recruiters often meet with many candidates as part of the recruitment process.  They need you to remind them of your candidacy and why you are the best person for the job.  The job application process does not stop after you shake hands at the end of an interview.  Go the extra mile and send a thank you note.  

Keep in mind the following guidelines when writing a thank you letter:

• Try to keep your thank you letter short.  If you need to come back on some points you felt were not properly addressed during the interview, do it concisely.
• Be conservative, yet personable.  Although you want to remain polite, being "too polite" might create a barrier.  Look at the thank you note as a continuation of the interview.  How was your rapport with the interviewer(s) when you left the room? 
• Thank each interviewer in a separate correspondence and make sure to write something different for each one of them (i.e. don't write one e-mail to the main recruiter and "cc" the others on that e-mail). 
• Don't wait too long before sending your thank you note.  Although views sometimes differ on this issue, sending a thank you note the day after the interview is recommended.
• Put as much attention in writing your thank you note as you did when you wrote your resume and cover letter.  You don't want the recruiter to see a typo this late in the process...   

The above tips were only meant to serve as general guidelines.  How you should follow-up after an interview is really up to you.  Use your common sense and don't forget... the race is not over until you've crossed the finish line.