Want to know who these companies are? If you have a ton of time to kill, you could make some serious side cash – or maybe just a few hundred dollars’ worth of gift cards every month.

Many of these companies simply want to track your behavior online so their clients can better advertise to people in your demographic. Keep in mind, that means not everyone will qualify for some programs — a company may be looking specifically for 25- to 34-year-old men in a certain region or income bracket, for example.

Even so, it doesn’t hurt to apply. So sit back, open your browser, and learn all the different ways you could be earning money for surfing the web.

Wonder

If you have excellent research skills and want to earn some extra cash, Wonder might be the perfect fit. We wrote about Wonder several weeks ago, and here’s how it works: Basically, Wonder invites anyone – journalists, corporations, or even individuals – to pay a flat fee for a properly researched answer to their most burning questions. In most cases, users pay this fee because they don’t have the time to do the research themselves, or because they want to make sure they get it right for an important presentation or report.

On the employment side, Wonder researchers pull out all stops to create accurate and comprehensive responses to any question posed. Wonder doesn’t have any formal education requirements for the researchers it hires, but it does prefer candidates with excellent research and English writing skills. If you’re interested in learning more, you can look into becoming a researcher on AskWonder.com, or read more about the company in our in-depth review.

Want to hear what people say about wonder? Nina R., one of the company’s expert researchers, had this to say:

I love working for Wonder because it allows me to do professional, interesting, engaging work on my schedule, which, as a stay-at-home mom, is priceless. The pay is good, the leadership team is fantastic, and I learn something new every time I sign on.

Swagbucks

For an easier way to earn that doesn’t require quite so much brain power, try Swagbucks. This website will literally pay you to search and play around on the internet, with almost nothing more extensive required on your part.

The set-up works like this: Once you sign up for Swagbucks, you’ll download their search bar onto your computer. From there, you’ll earn points for shopping online, watching targeted videos, searching the web, and taking surveys. Once you rack up a ton of points, you can exchange them for gift cards to popular retailers like Amazon.com and Walmart.

So yes, Swagbucks pays you in gift cards and not money. But most people can turn those gift cards into cash if they’re creative – for example, you can score some Walmart gift cards and use them for groceries, then turn around and reduce your grocery budget that month. That’s pretty swank if you ask me!

Related: Guide to the Gift Card Economy

Opinion Outpost

You know what they say about opinions, right? They’re like armpits (and other less savory body parts) – as in, everybody’s got ’em. The good news is, Opinion Outpost will actually pay you for voicing your opinion, answering important questions, and taking their surveys. That’s right: Whoever said your opinion didn’t matter was dead wrong.

All you have to do to get started is sign up with an email account or social media account. Once you do, you’ll be selected for surveys you can complete in exchange for cash or gift cards to retailers like iTunes or Amazon. Plus, you can also earn entries into occasional cash drawings for as much as $10,000.

User Testing

User Testing is another online survey site that rewards its members for giving their opinions on marketing tactics and products. Worldwide, more than 34,000 customers and companies rely on UserTesting to figure out marketing techniques and strategies and to gain insight into the minds of their users.

Signing up is free and easy. Just for visiting a website or testing a new app, you can get paid $10. Of course, participating in multiple campaigns can help you earn more and more cash over time. And each time, you’re paid $10 for about 20 minutes of work or less. It doesn’t get any easier than that.

Smart Panel

Earning nominal amounts of cash is easy with Smart Panel. Once you complete a three-minute questionnaire to see if you qualify, you can get paid for everything from living and breathing to using your phone or computer like you always have.

For starters, you’ll get $5 just for meeting their qualifications. After that, you’ll get another $5 per month just for keeping the app installed. Beyond those initial payments, you’ll earn small amounts of cash just for using your phone or computer as you always have – and letting Smart Panel analyze your search results. According to Smart Panel, you can earn up to $110 in 12 months and up to $230 in 24 months – for doing almost nothing.

Here’s why user Huy had to say about Smart Panel:

My absolute favorite thing about Smart Panel is how my interests matter and contribute to digital products and services. If I were to recommend Smart Panel to my friends, I would simply say “Download this! You can thank me later!” My participation in Smart Panel is stress-free as it is easy to use. I simply followed the instructions to install the application on my mobile device.

mobileXpression

While mobileXpression doesn’t dole out a set rate of cash, installing the app and answering an array of questions does put you in the running for all kinds of rewards and free merchandise. Once you install the app on one of your devices and keep it installed, you can earn everything from Amazon gift cards to electronics like iPads or flat-screen televisions, just for searching the web as you normally would.

The requirements are simple: First, you need a device that’s compliant with their software, and second, you must sign up and meet the program’s qualifications. After that, the software works independently on your device, analyzing and researching your usage with no extra effort on your part.

Inbox Dollars

If you love watching online videos (who doesn’t?), Inbox Dollars wants to pay you to live your dream. In addition to watching videos, you can also get paid for taking surveys, reading emails, playing games, shopping online, and even searching the web. Does it get any better than that?

According to the company, its users have earned more than $43 million to date. Plus, signing up is free and easy: Simply enter your email, create a password, and you’ll even get $5 in bonus cash for joining. After that, the amount of money you’ll earn is based on how many tasks you can complete.

Small Business Knowledge Center

This is a weird one, but it works nonetheless. Basically, a company called the Small Business Knowledge Center will pay you (in gift cards) for your junk mail – both the physical kind that comes in your mailbox, and even your email spam.

You might be questioning the sanity of a company that pays for stuff most of us throw away, but it is legit. Clients in the financial services and insurance industries “use this information for competitive intelligence and product development purposes,” according to the SBKC website.

If you sign up and qualify, you’ll be rewarded with gift cards just for sending your pesky junk mail! Who knew?

MyPoints

You heard it here first, folks: MyPoints.com is yet another cash-back site that will reward you for shopping online and printing coupons. If you already do most of your shopping online, for example, you can score meaningful benefits on everything you buy, earning points you can redeem for gift cards and more.

Plus, you can sign up for the chance to win an Amazon gift card or earn one right away for spending at least $10 at a selected online store, such as Walmart.com, Target.com, or Amazon.com. If you need to buy stuff anyway, then this is a smart way to rack up rewards at the same time.

Survey Junkie

Like some of the other options on this list, Survey Junkie pays you to…..wait for it…..take surveys! Signing up is free and you can be on your way to answering important survey questions for companies in no time. When you do, you’ll earn virtual points you can redeem for Paypal funds or electronic gift cards.

But, how much can you earn? It depends. You earn between 100 and 200 points for most surveys, but you can’t cash out your points until you reach a threshold of 1,000 points, which is worth $10. So, on the high end, you’ll get paid $10 for completing five surveys. While that’s not a lot of money, it’s too easy to mess up.

The Bottom Line

If you want to earn some extra cash, the internet has paved the way to more options than most people realize. Just by answering survey questions, watching television, or doing your regular online shopping, you can earn real cash rewards or, at the very least, gift cards that can be used to buy the stuff you want.

Every site we covered here is absolutely free to sign up for, although not everyone will qualify all the time. Still, if you want some almost-free money for doing stuff you were planning to do anyway, it’s hard to complain.