The goal is to regularly provide proof to both your professional network and to selected potential employers that you are highly competent and will be a decided advantage to their organization.
Some people don't know what github is and won't care, others really like live sites even if they're modest, and still others really just want to see resume bullet points about dollars saved / created. Eventually you can put all of that together, but naturally it'll help when your prospective hiring manager has the same ideals you're demonstrating with your portfolio.
Portfolios are secondary to name recognition and social proof. Let me reemphasize that sharing your goodwill, your skills, and your successes with your professional network is probably more valuable than anything else you can do - develop a local or national reputation as a top gun and work will come to you as long as you keep your connections warm.
As a small company owner I want to completely endorse this comment. These "proofs" of a developers skills and technical interest are the hard requirements I have before conducting any interview. Naturally the "social proof" is also important but less common and more difficult to attain.
Even tiny personal projects demonstrating ones interest in keeping up with newer hot technologies like node, redis, backbone, etc mean a lot.
tl;dr Having a set of quality personal projects (github, live, whatever) is absolutely critical.
Some people don't know what github is and won't care, others really like live sites even if they're modest, and still others really just want to see resume bullet points about dollars saved / created. Eventually you can put all of that together, but naturally it'll help when your prospective hiring manager has the same ideals you're demonstrating with your portfolio.
Portfolios are secondary to name recognition and social proof. Let me reemphasize that sharing your goodwill, your skills, and your successes with your professional network is probably more valuable than anything else you can do - develop a local or national reputation as a top gun and work will come to you as long as you keep your connections warm.