It’s a bit misleading to say you can make money on the Internet in a fast, efficient way starting from scratch. For most gigs you’ll need a profile. But the Internet does provide excellent and multiple avenues to offer your services. Even if you’re not pitching a particular skill, register at the Harvard Business School Computer Lab here or register to participate in a 20|20 Panel — if selected you might make $100 in an hour just for answering questions.
If you have skills in writing, programming, research, musicianship, carpentry, design or even comedy, there are incredibly rich marketplaces like Elance, Upwork, and Fiverr where you can sell your services fast just by adding a profile listing your skills. (Note: the longer you’re in business there, the more money you’ll make, so patience on the Internet — just as in real life — helps.) Make sure you set up a PayPal account, too. If you’re looking to make money, you have to make it easy to get paid.