Lots of faucets are using a service called Microwallet as a place where payments are stored before being sent to you.
When a transaction takes place on the Bitcoin network it is sent to the blockchain where it is confirmed (this takes time) and a transaction fee is charged. With Microwallet the owners and operators of faucets send coins to an address and they are stored to later be divided up off the chain immediately.
This allows for faucets to send a message to the Microwallet site saying that you have received some coins and they move it internally from the faucet address to your Microwallet address. Once you have reached a threshold the coins are available to you as an end user to be withdrawn which is when the transaction goes back on the blockchain.
By using a site like faucethub.io it is easier for a faucet owner to send you micro transactions and saves you the fees by bundling up transactions as well.
What makes this such a cool service is that once you have reached the withdraw limit you do not have to do anything. The coins are automatically sent your Bitcoin wallet address, plus you don not have to do anything to actually get your Microwallet setup. It automatically exists when you use your coin address on a site that supports Microwallet.
Microwallets are completely trustworthy, the developers are active on various platforms and the always payout on time. The Microwallet used by this website is faucethub.io and is completely trustworthy.
While Microwallet is not a true wallet but more of a temporary storage space for small transactions it is completely reliable and home of several crypto faucet payouts.
There have been several popular microwallet providers in the past. Like Xapo, FaucetBox, Epay and FaucetFly. Most have stopped, or are almost dead services for various reasons.
At the moment there are only three still very active and reliable:
FaucetHub might not be the most user friendly microwallet when you first visit the website. But, after registering it looks really good and gives you a lot of options. Most important of those are the faucets. They have a large collection of faucets for several crypto coins, including Bitcoin.
Maneuvering through all the faucets listed can be a real hassle. as many people register a faucet there and some just use this to entice you to download malicious software.
Or, some are just very difficult to claim. Having to complete multiple captcha's and visit many pages before you can actually claim.
It's best to either make your own faucet list, or use one of many made by other people, like the one on this website next to the actual faucet.
Faucet System is a more easy microwallet where you do not need to register, although you can. Just claim with the same wallet address at multiple faucets and you will be automatically paid every Monday after reaching the minimum threshold of 25.000 Satoshi.
They have their own nice rotator for easy claiming.
You can always check you balance just by filling in your wallet address you used for claims.
Coinpot is a private microwallet. Unlike FH and FS they do not accept other faucets for their services. All coinpot faucets pay directly to your coinpot account. When registering to any of their faucets, you are automatically registered with coinpot.
Payment threshold are the standard in this field and payment methods are really easy. You can convert any coin to any coin within their system. This is not a exchange, but just easy if you claim from various faucets to convert them all to your desired coins.
You can request to payout to other Microwallets, Xapo, Coinbase or your own private wallet address.
To find all coinpot faucets in one place, please visit the extras section.