http://www.nytimes.com/2008/12/28/business/28digi.html
This analysis of the cost basis of providing SMS service was interesting also.
Senator Herb Kohl, Democrat of Wisconsin and the chairman of the Senate antitrust subcommittee, wanted to look behind the curtain. He was curious about the doubling of prices for text messages charged by the major American carriers from 2005 to 2008, during a time when the industry consolidated from six major companies to four.
So, in September, Mr. Kohl sent a letter to Verizon Wireless, AT&T, Sprint and T-Mobile, inviting them to answer some basic questions about their text messaging costs and pricing.
All four of the major carriers decided during the last three years to increase the pay-per-use price for messages to 20 cents from 10 cents. The decision could not have come from a dearth of business: the 2.5 trillion sent messages this year, the estimate of the Gartner Group, is up 32 percent from 2007. Gartner expects 3.3 trillion messages to be sent in 2009.
This analysis of the cost basis of providing SMS service was interesting also.
Perhaps the costs for the wireless portion at either end are high spectrum is finite, after all, and carriers pay dearly for the rights to use it. But text messages are not just tiny; they are also free riders, tucked into whats called a control channel, space reserved for operation of the wireless network.
Thats why a message is so limited in length: it must not exceed the length of the message used for internal communication between tower and handset to set up a call. The channel uses space whether or not a text message is inserted.
Professor Keshav said that once a carrier invests in the centralized storage equipment storing a terabyte now costs only $100 and is dropping and the staff to maintain it, its costs are basically covered. Operating costs are relatively insensitive to volume, he said. It doesnt cost the carrier much more to transmit a hundred million messages than a million.