I also participate in online surveys through the following websites, that work in the US and internationally (I use them all and I'm based in Brazil, for example) - Opinion Bureau, Myiyo, and Green Panthera. All of them have a variety of surveys and pay well. All you need to make money is to have 20 min or so to answer a few questions every day/week and have an active Paypal account so you can cash out.

One major part of any design process is checking to make sure that what you’ve created actually works as it is intended – so there are a ton of websites and apps out there that need to be checked, and you could make some extra money by being the one to test them! Testers are usually paid by the test, and it’s often only around $10 per test – however, $10 for a few minutes of your time isn’t bad! You’ll generally be given a website or app to look at along with a series of instructions on what you should try to do – then you’ll either have your voice and screen actions recorded or you’ll write a short report afterward on how well the website or app worked. That’s it.

Matched Betting (not available in the USA) enables you to gamble (nearly) risk-free. I say nearly as there is always room for error! It involves placing bets on all outcomes of an event, using free online bets given out by the Bookies. Although it may take a while to get your head around the concept, Matched Betting can make a substantial addition to your monthly income.
Some of the best things in life are free and market researchers love to hand out new products in exchange for consumer feedback. If you like to try new products and have the opportunity to try them out for free, do some research and find the market research companies that offer products you desire to try. You can join campaigns and they will send the products or coupons to you to test them and provide feedback. You will generally have to fill out surveys and provide written reports based on your opinions. You will get to keep the products and they will sometimes even send you a monetary gift as an offer of thanks for doing the work.
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