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