Just imagine how much it costs to make a hard copy of your portfolio in high quality paper and top-notch printing. Then multiply it by ten. It's enough to feed you for a week! Then imagine having an online portfolio that will cause you next to nothing and be flexible enough to send to dozens of employers and affiliates. Which one do you prefer?
Gone are the days when you have to print countless copies of your portfolio and distribute them to possible employers. In five minutes, you can set up a website that features your best works. Online portfolios serves the functions of the old-school portfolios and more. E-portfolios can widen your reach and attract opportunities you haven't imagined in the first place.
Many professionals think a blog is enough to showcase their strengths, but it's not. A blog is a good way to network with people from your profession, but it's insufficient in presenting the body of your work. To highlight your best works, you need a portfolio to do it for you.