^ Matthews, H. Scott; Eric Williams (28 February 2012). "Telework Adoption and Energy Use in Building and Transport Sectors in the United States and Japan". J. Infrastruct. Syst. American Society of Civil Engineers. SPECIAL ISSUE: SUSTAINABILITY OF TRANSPORTATION AND OTHER INFRASTRUCTURE SYSTEMS (11): 21–30. doi:10.1061/(ASCE)1076-0342(2005)11:1(21). ISSN 1076-0342.
If you're serious about making money online, start a blog. Blogging is one of the easiest and most sustainable income sources. As long as the blog is setup the right way, in the right niche, with the right content targeted at the right audience, and the offer is complementary to the content, you could make a tremendous amount of passive income from a blog.

Research individual companies in your desired niche: If possible, it’s always better to become an affiliate directly with a company (if they have an internal affiliate program), as no one else will be dipping into your commission rate. This is the preferred route for most of the prominent affiliate marketers, including Pat Flynn. Unfortunately, it’s also the most work, as you’ll have to do the research yourself to see who offers programs (they’re usually listed in the website footer).
A site called User Testing will actually pay you a fee to evaluate websites. It typically pays you $10 for each video that you review – which typically takes about 20 minutes. If the work is there, and you are particularly good at it, you could earn up to $30 per hour. That’s a pretty solid pay rate for a work-at-home job. You wouldn’t have to work a whole lot of hours to generate a decent part-time monthly income.
Robo-advisors are diversified investment accounts that are automatically managed by a computer algorithm (as opposed to a human money manager). If you want to invest, but don’t have the money, or don’t want to invest with a money manager, robo-advisors are for you! Robo-advisors make investing easier—and cheaper—so they’re perfect for new investors.