If you are a professional photographer, or have a real flair for photography, then selling your images on other sites could be an idea. This could be done alongside your own photography site, as it is a good way help get your work viewed by a wider audience. There are numerous stock image websites to contribute to, but choosing a popular high-end site like Shutterstock should ensure your photographs make you some money.
Check if you need a model release. Photos of people can only be sold for commercial use if they've signed a 'model release' that gives you permission to use their image (children need a parent/guardian to sign). Without a release, these photos can still be sold for editorial use, as long as they were taken in a public place – eg, if you submitted a 'breaking news' shot with people in the background. If there's any doubt, always ask permission.
Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online.
If you don’t mind doing other people’s chores, then TaskRabbit is a great option for making money online. Earn extra income by walking your neighbor’s dog or mowing Mr. Smith’s lawn. It might seem like not the most lucrative option, but the top taskers reportedly earn as much as $7000 a month, making this a full-time way to make money online for some.
Now, making money online should seem like a pleasurable activity. Why wouldn't we do just about anything to see things through, since it would be a major source of pleasure, right? Wrong. In the beginning, like anything else, we might get really excited about it. We might also set our hopes very high. But that all comes crashing down when we begin to fail.
If you have a background in a specific field, you may find there is a demand for writing industry papers in your area of expertise. For example, there are often adverts for doctors, lawyers, nutritionists, and business experts from particular niches, to write white papers on different subject areas. These are well paid jobs that you will need to stake your reputation on, but that can often be worked on from the comfort of your own home.
These are sites that post short tasks that pay per piece. These tasks may involve anything and everything, including data entry, writing, tagging, surveys, and more. Most don't pay much per piece, but the key to earning substantial extra money with them is getting fast at the tasks you do accept. Below are a few sites to consider trying that pay for short tasks:
Do you know there are companies and people out there that make some pretty good money offering their cleaning services to households and companies? They'll come in and charge you either a set fee per room or an hourly fee to clean up. They can come weekly, monthly, or whenever you think you need some extra scrubbing. What's the point? Why not have the person they hire be you?
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. 
Is there a product or service that you are particularly enthusiastic about? If you are, you may be able to develop a website that is built around selling it. You don’t have to be the actual provider of the product or service either. There are many businesses that offer these products and will allow you to sell them on an affiliate basis. For example, you may be able to sell a product on your website for a commission of 20% or 30% of the sale price.
It’s not the sort of online money making opportunity that’s covered in glory, but everyone needs a set of eyes to make sure the numbers add up at the end of the year. Every business and most individuals need someone to help prepare tax returns, especially time or resource-strapped small business owners. The Income Tax School provides an array of training programs that'll certify you with tax prep in as little as 10 weeks, and once tax season rolls around you'll be able to charge an average of $229 per return as a freelance tax preparer with this side business idea, reports CNBC.
Here’s a good example of how lead sales can work in real life: My second website, Life Insurance by Jeff, brings in a ton of traffic from people who are searching the web to find answers to life insurance questions. While I used to have the website set up so I could sell these people life insurance myself, it was a lot of work to process all the different requests and clients. As a result, I started selling the leads I gathered instead.