In the world of Bitcoin, there are what are called bitcoin faucets that will pay out very small amounts of free bitcoins for visiting different sites and looking at advertising, or for completing tasks such as completing captchas with advertising displayed around it. You need to have a bitcoin wallet address to use these, such as a mobile and web based wallet, or a desktop bitcoin wallet such as Bitcoin Armory, Here on BitcoinsInIreland we maintain an up-to-date list of bitcoin faucets here. You can also read a more in-depth article about faucets by clicking here.
These generally work in a way where you give a bitcoin wallet address to the site (best to make a specific one called “Bitcoin Faucets” so you can track your earnings, and then you begin to generate small (ie ~0.00000020 btc) amounts for each task. Most of the miners who process bitcoin transactions do not accept amounts for less than 5430 satoshis (0.00005430 BTC). Anything below this is called bitcoin dust, so bitcoin faucets employ microwallets between them, and when you hit the payout threshold, it is sent on a scheduled time, and then will take some time (from hours to days) to hit your wallet. But within a day or two time and effort of using the different sites, you can get your first free bitcoins. See an example of my first bitcoin faucet payout is in the screenshot below.
Bitcoin Faucet Terminology
Just for reference, using a fixed value of 1 bitcoin $500/€380
1 thousandth of a bitcoin = 1 millibitcoin = 1 mMTC = 0.001 bitcoin = $0.50 / €0.38
1 millionth of a bitcoin = 1 microbitcoin = 1 μBTC = 0.0001 bitcoin = $0.05 / €0.038
Smallest bitcoin unit = 1 satoshi = 0.00000001 bitcoin = a very tiny amount