The Stamps.com system, called NetStamps, requires special software and adhesive, watermarked paper available from the company. As many as 25 stamps can be printed at a time, the company said. NetStamps can also be printed for any amount for any class of mail, including international mail.
The Santa Monica, Calif.-based company said the NetStamps system differs from other online postage systems, which often require people to use stamps the same day they are printed, and to print stamps directly on an envelope.
The USPS first introduced its online postage service, called PC Postage, in 1999. Nearly 390,000 people are registered for the service, said Postal Service spokeswoman Monica Hand.
NetStamps requires a personal computer with an Internet connection and a printer. A pack of 125 labels costs $3.99. The company also charges a monthly service fee, along with the cost of the postage.