Sometimes by the time a job gets advertised, it's already too late to land the position. The posting may just be a formality if the person doing the hiring already has candidates in mind, candidates who were in turn alerted to the opening by people who knew about it before it was advertised.
That's great if you're the person who cut to the front of the line. It's dramatically less good if you are stuck applying for a job without knowing if your resume will even be looked at.
In the job search, who you know matters. That's why it's incredibly important to activate and use your network early in your job search.
Take a team approach
If you are out of work, you can use social media to broadly broadcast that you are available. That makes it more likely that your obscure contacts -- the people you would never even think of -- will know about your search. You never know when a friend of a friend or someone you barely know will offer a tip or mention your name in a way that helps you.
Of course, if you have a job things get a little harder. In that case, you should reach out to people you know well and tell them what your situation is. Let them know you are looking and what your goals are.
It's important to reach out to people directly, even if your job search is public. People generally like to help others when it does not require too much effort on their part. By involving people personally, you create a better chance that your network will be thinking about you and will mention your name if an opening comes up.
Grow your network
You're not limited to who you know now. Get out there and meet new people to grow your network.
This can be as simple as attending industry events. Many industries have trade shows, or even after-work mixers or cocktail hours. Some have trainings or even career development opportunities.
You can also reach out to people you want to know. You may get rejected or ignored, but there's no reason not to ask people for an informational interview (an interview where there is no specific job being filled), or even an informal cup of coffee.
Be positive and persistent
Remember that networking is a two-way street. Work hard on behalf of the people you know when they need something, whether it be a job or a recommendation for a good barbecue place in Boston. In many ways, you get back what you put out when it comes to your network. If you interact and engage with people they are much more likely to put in effort on your behalf.
The job process can be frustrating. Sometimes leads go nowhere, and promising situations fizzle out. No matter what happens, stay positive and keep working at it.
Sometimes you will get an interview because someone you know professionally was just waiting for someone like you. In other cases, your cousin's hairdresser knows someone at the company you dream about working at. Put yourself in a position so you are ready no matter where opportunity comes from.