If you live in Australia you can use a website called cashrewards to receive a small amount of cash and in exchange they get a bit of information about your purchase.

The way it works is that you create an account (referral code: http://fbuy.me/fscmf) and then you use their links to navigate to the shopping page. There are a huge variety of businesses on cashrewards that I regularly take advantage of.
From there, your sale gets tracked and you can then get paid back a proportion (usually 1-5%) of how much you spent into your account. From there you can transfer the money to your bank account. It's not a lot, but as someone who purchases a lot off eBay it's nice to have a little bit of money back every so often.

Few pro-tips:
Always look on cashrewards first
Turn off your ad-blocker because that might cause the sale to not get tracked
Keep an eye out for deals where they up the cashback

Lastly, if you shop at Woolworths make sure you buy vouchers through cashrewards - the money is deducted from the sale immediately