The easiest way to earn money through Internet work, usually called telecommute work, is to negotiate to have your existing job with a company or government agency modified for telecommute. As an example, Fair Point Communications (that took over from Verizon in the Northeast a few years ago) provides 24-hour technical service from telecommute technicians working from their homes. Government agencies at all levels (municipal, state, federal) are often amenable to telecommute changes because it saves them money, reduces certain overhead costs, allows people with certain disabilities to continue working, and eliminates some of the negative impacts on the ecological and urban environments.
There are, on the other hand, viable options that were modified or designed specifically for telecommute Internet work. These are however serious jobs, just like any other, and have stringent qualification requirements and therefore--like any job--are not easy to get. There are basically 5 categories of jobs designed for Internet employment.
The category you are at the moment in contact with is Internet educational sites offering e-education opportunities, such as eNotes.com. There are similar sites that also hire e-educators. There are also sites offering one-on-one tutoring. All have stringent qualification requirements.
Another is Internet virtual office assistance. These jobs vary from telephone receptionist to secretarial to data entry positions. Only highly qualified applicants are accepted through the application, screening, and testing procedures. One such company is Cloud10.com, a "virtual call center" that is headquartered in Denver, CO. Speaking of calls, there several companies that take questions and send answers in the SMS text message format: ask anything you want to know as a text message and get an answer! One of these companies was founded by the same man who gave the world voice mail! Another originates in the UK but has a US presence. These hire researchers who answer the SMS questions. As with the others, the qualifying and training requirements are stringent and the work demanding.
Magazines with an on-line edition and e-zines do periodically have openings for staff writers. The openings are advertised on their site under Careers, Work for Us, Jobs, or About Us. An example of an e-zine that often has positions open is About.com. Another is LoveToKnow.com. These differ from other popular e-zines in that these offer payment for services.
That leaves the last and most prevalent category: freelance work. Freelance work can be in writing, photography, medical specialty, computer technology, graphic design, or many other fields, though writing is the most popular. There are a number of sites devoted to bidding for freelance jobs, like IFreelance.com and Project4Hire.com. There are also platforms where freelancers can offer their services with posted rates and answer requests that are made directly to them. A good example of this is LivePerson.com, with members all over the world. You can earn money on the Internet through telecommute work if you are qualified and fortunate.