Which of the following is true about purchase methods for stamps?

The assertion that stamps can be purchased via various methods including ATMs, mail, and phone accurately reflects the multiple avenues through which customers can obtain stamps. This flexibility allows customers to choose the purchasing method that best suits their needs or preferences.

Stamps can be bought at specialized postal kiosks and ATMs that provide USPS services, making it convenient for individuals to quickly obtain stamps without visiting a post office. Additionally, customers can purchase stamps through mail by ordering them directly from the USPS or other authorized sellers. Furthermore, while purchasing via phone may not be among the most common methods, it is true that certain services allow users to place orders over the phone.

This comprehensive approach ensures that customers have access to stamps in various ways, catering to different circumstances and preferences, which aligns with the multiple scenarios in which stamps can be obtained in practice.