Techniques are described for providing a storage service that stores information about large numbers of transactions in a persistent manner, such as with a high degree of reliability, availability and scalability based at least in part on use of a distributed computing and storage system. In some situations, the transaction information storage service stores various information about transactions that each include at least one monetary payment (e.g., a micro-payment) between financial accounts of two or more of numerous users having accounts with one or more entities. The transaction information storage service may be provided by or otherwise affiliated with a merchant, and customers of the merchant may purchase usage of the storage service for programs executed by or otherwise affiliated with the customers, with the storage service available to remote executing programs via a defined API of the storage service, such as a Web services-based API.