On a normal faucet, you will enter your wallet address, solve a captcha and be rewarded with Satoshi instantly. More often than not you will get a pop-up screen or a 2nd captcha to solve before you can get the payout. Most payout in 0 to 15 minutes some as long as a day.
Some of these faucets instant pay you to your FaucetHub but some need a minimum payout. They may be good and bad. You need to find out that they are not scamming.
Now a day Autofaucet are very popular(i.e. Faucetworld.in, Firefaucet). These faucets are very easy where you don’t have to solve captcha or shortlink multiple time. You do only one time and their page automatically refresh at regular interval and they pay you without your manual efforts.
People who run websites are usually earning from Ad networks and shortened links. It is basically a win-win situation. So you don’t need to worry about it. Go and start earning.