Windows Phone 7 smartphones went on sale today at AT&T and T-Mobile retailers in the U.S., although customers are not exactly breaking down doors to buy them in the early going.

Analysts said they expect WP7 sales to build slowly as the holidays approach, especially with a record $500 million TV advertising campaign for the devices.

Neither carrier responded to a request for comment on WP7 sales midday Monday. However, one sales representative for the AT&T store in Framingham, Mass., said a reporter's phone call at about noon today was the first inquiry about WP7 phones at all. He predicted growth in interest in the next two weeks.

Verizon Wireless, the largest U.S. wireless carrier, expects to sell WP7 phones next year, a spokeswoman confirmed.

Full story: Computerworld