Hold a yard sale. If you have a yard or garage and plenty of items to sell, you can have a yard sale as early as tomorrow. By advertising your sale on local Facebook pages and Craigslist, you can also skip the paid newspaper ad and keep all of the profits for yourself. If you don’t have time to price everything, try asking patrons to “make an offer” or grouping similar items on tables with an advertised price (e.g. everything on this table is $5).
Banner advertising, when set up using a system like I presently use, can be very hands off – in fact for me it’s entirely passive – assuming there is an audience that the sponsors benefit from advertising to. It’s difficult to make loads and loads of money just from banners unless you have significant traffic, but it is easy enough to make some money from it and once you do, it generally proves very reliable unless you stop updating your website.
Teaching and tutoring English as a second language is a great way to make money online, not to mention open some doors for you to travel the world if you'd like. While full ESL (English as a Second Language) accreditation is recommended, as long as you’re a native speaker and have the ability to teach, there are people in countries such as Hong Kong or the UAE who are willing to pay upwards of $25/hr for you to tutor them English via Skype. Check out Indeed, Learn4Good and Remote.co for remote english tutoring jobs or sign up on a specialized site like VerbalPlanet or Chegg Tutors.
Creating a jobs board website can be another profitable venture. The ‘jobs’ field can be quite saturated, so it is important to find a niche that is still crying out for a jobs board website. Monetize this type of site by charging businesses to list their jobs on your site. Those searching for jobs could also be charged a fee to access the higher paying job adverts.
Amazon will have you work on micro-projects that require some sort of human interaction. Tasks can include translating a paragraph into English (or another language), rating the search results for certain keywords, or reworking an article. The tasks are simple, and you will be paid a small amount to complete each. But if you do enough tasks quickly, you can make a respectable amount of money.
However, like anything else truly worthwhile, apps require a significant investment of your time or money upfront. If you don't have the skills, then you have to hire someone who can assist you in creating a great app. But first you need to come up with an idea that will sell. Do the proper market research and analytics to come up with the right app.