Amazon is certainly not the only player. James Staten, an analyst at Forrester Research, said Akamai Technologies Inc., Enki and Terremark each offer at least a portion of the Web services Amazon is selling. IBM Corp. and Sun Microsystems Inc. offer pricier versions aimed at big businesses, while Google Inc. and Microsoft Corp. are thought to be working on services similar to Amazon's.
Amazon comes closest to utility-style billing, Staten said. Most competitors demand a contract or minimum payments.
Amazon, which gives away the computer code to access its services, bases its fees on how much data is shifted around and stored. For example, the company charges 15 cents per month for every gigabyte of data stored in its Simple Storage Service. Developers pay another 10 cents each time they send a gigabyte into the cloud and 18 cents per terabyte when they pull data back out.