For some reason, the resume and cover letter are still perceived as the only must-have documents in the application package. Although sending a thank you card or letter after the interview is generally considered a good thing, few people actually do it (mostly because job seekers don't believe it can have any impact on the decision making process). The truth of the matter is that when it comes to job search, every detail matters. You never know who is going to review your application and how that person will approach the decision-making process. Very often small things like follow up with a post-interview thank you email can make all the difference. Now we have to be honest here - it is true some HRs don't really care about a thank you letter. But at the same time, there are many of those who do think that a simple thank you email shows good manners and true interest in the job. So it can only bring good, really. The worst case scenario is that it will be just ignored. In other words, it's a win-win.
Following Up After an Interview
Writing a thank you email/letter after an interview doesn't take much time. There is nothing complicated about it; you don't really have to play around with the structure or formatting as you did with your resume. Sending a thank you letter reinstates your interest in the job as well as demonstrates your ability to follow through. Think about it if you were the one making hiring decisions. If you had two equal candidates but only one of them had sent you a post-interview thank you card, whom would you select for the job? Again, it's not that you have to deliver something sophisticated. In most cases, a simple email is more than enough. Pretty much the only rule is don't copy-paste your thank you letter from the internet.
Yes, there are wonderful templates available online. Yes, they sound like exactly what you want to communicate. Yes, they probably were written by people who have experience in the field of career advice. But here is the catch - those templates were not written based on the interview that you had. And this becomes crucial because this letter is meant to be personalized. Otherwise, it does no good whatsoever. Instead, remember how the interview went. There probably were some things that didn't go exactly the way you planned - this is your opportunity to fix them. If there was a question you didn't answer quite right, re-address the issue in the letter. You don't have to read the how to write a thank you note tutorial for that. Just be yourself. Don't try to be someone else. So while you can take ideas from sample thank you letters, don't just copy-paste because "it sounds just right".
Lastly, be brief. There is no need to go over half a page to thank your interviewer. No one likes to read lengthy thank you letters. HRs are busy people and they have already enough things to deal with apart from reading post-interview thank you notes. So be concise. All you have to do is to restate your interest, thank the interviewer, and address one or two issues that came up during the interview. It can sometimes be stressful and you may even find yourself over analyzing this for a couple of hours. But keep in mind that this letter is one step that will likely put you a step above the crowd.
If you are going to send an email thank you letter, you have to think about a professional subject line. There, you have to provide information about why you are sending this email. The best thing to do it is to include your name or the job title and the phrase "Thank You".