Q. I applied at a company three years ago for a position and never heard anything. Is it appropriate to apply again for another position they are advertising now?
A. Absolutely. Three years ago or even three months, if you haven’t heard back
from a company, and they have opportunities which interest you, and for which you are qualified, apply! Just because you didn't hear back before, doesn't mean it will happen again.
There are many reasons applicants don’t get responses from companies but there are things you can do to market yourself and help you stand out against other applicants. For instance, If you applied online, you may not have made it through the initial screening tool. Make sure you have plenty of key words which show just how qualified you are for the position and reflect the breadth of your skill sets.
Perhaps you responded to an ad, and were just one of many cover letters in the pile. If your letter was addressed “To whom it may concern, Dear Sir or Madam or Attn: Hiring Manager”, chances are you didn’t make the cut. Do the research and determine the name of the hiring manager and adress your cover letter accordingly. If you can't find the hiring managers name, get the name of someone who may know that person, and include that persons name in the letter and the subject line of the email as a 'referred by' reference.
You can also leap frog the whole pile by having an employee you know or someone familiar to a person in your nerwork who can hand carry or email your resume or even make a call to the person running the process. You may think you don’t know anyone, but invariably someone you know is likely to have a connection.
Get on LinkedIn, carry your target list of companies with you, and ask everyone you meet if they know anyone.
Finally, if by some chance, you are not qualified for the role, and that is why you didn’t hear back, do everything possible to get noticed by the hiring decision makers. You can do this by connecting with them on LinkedIn and writing thank you notes for considering you application. If they hadn't seen your resume, a personal note may prompt them to take a look. You never know when an oppportunity more appropriate for you will open and leaving a lasting impression puts you in a better position to have them contact you the next time. Good luck!