Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
Posting ads on Craigslist is technically easy, but people often have fears about posting their personal information on the site. I communicate mostly through email when doing business on Craigslist, and I’ve never run into any issues. I’ve never been ripped off, nor have I been murdered or raped for using the site. It takes common sense, so use your best judgment, but don’t assume someone is a thief just because of their preferred communication method. For an extra bonus, google “funny Craigslist ads” to see some delightful examples of guerilla and grassroots marketing.
Cafe Press: This website allows you to create digital designs that can then be sold on the platform. You'll earn a commission for everything that sells and you'll never have to deal with printing, warehousing, customer service and so on. The site has over 2 million independent designers that have created products being sold online here. If you have some graphic design skills, then this is a great potential source for your web-based income.
If you are great at typing fast and transcribing, this is for you! By signing up at Transcribe Me, you get to work on tasks where you are expected to turn audios and videos into text form. What’s more, you get to determine your work schedule and have the opportunity to have a career progression. All that you need is a computer connected to the internet and your transcription skills. Tracking of your weekly work is easy and in real-time. You also get to request for your payment at anytime as long as you have a minimum balance of $20. This is released in a fast and secure way through PayPal every Thursday before 9 a.m. EST.
Merch by Amazon is another service offered by Amazon that will enable you to make money online without any initial outlay. To get started you need to create an account with Merch by Amazon. Then simply design some T-shirt logos or slogans, and upload them to your Merch account. You will need to choose a T-shirt type, color, and price, and Amazon will create product pages for each T-shirt. When someone makes a purchase, Amazon takes care of production and shipping. And you are paid a royalty for your design.