Primecoin (XPM) is a peer-to-peer open source cryptocurrency that implements a unique scientific computing proof-of-work system. Primecoin's proof-of-work system searches for chains of prime numbers. Primecoin was created by a person or group of people who use the pseudonym Sunny King. This entity is also related with the cryptocurrency Peercoin. The Primecoin source code is copyrighted by a person or group called “Primecoin Developers”, and distributed under a conditional MIT/X11 software license.
Primecoin's algorithm, however, computed chains of prime numbers, the results of which were published on its blockchain's public ledger, available for use by scientists, mathematicians, and anyone else. Use of a proof-of-work system to calculate chains of prime numbers was an innovation that produced useful results while also meeting the criteria for a proof-of-work system: it involved a calculation that was difficult to perform but easy to verify, and the difficulty was adjustable. Shortly after its launch, some trade journals reported that the rush of over 18,000 new users seeking to mine Primecoin overwhelmed providers of dedicated servers.
Primecoin faucets are a reward system, in the form of a website or app, that dispenses free primecoin in the form of a primetoshi, which is a hundredth of a millionth XPM, for visitors to claim in exchange for completing a captcha or task as described by the website. There are also faucets that dispense alternative cryptocurrencies. Rewards are dispensed at various predetermined intervals of time. Primecoin faucets usually give fractions of a primecoin, but the amount will typically fluctuate according to the value of primecoin.
Free primecoin faucet is a great way to help introduce new people to primecoin, or to your favourite altcoin. Many faucets provide information to newbies as well as offering them some free coins so that they can try before they buy, experimenting with a test transaction or two before putting real money on the line. Since this whole area is so new and a bit scary to some people, who perhaps don't quite trust it with their hard earned cash yet, this is a great way to promote digital currency and bring in new users.