A micropayment is a financial transaction involving a very small sum of money and usually one that occurs online. A number of micropayment systems were proposed and developed in the mid-to-late 1990s, all of which were ultimately unsuccessful. A second generation of micropayment systems emerged in the 2010s.
While micropayments were originally envisioned to involve very small sums of money, practical systems to allow transactions of less than US$1 have seen little success.[1] One problem that has prevented the emergence of micropayment systems is a need to keep costs for individual transactions low,[2] which is impractical when transacting such small sums[3] even if the transaction fee is just a few cents.