750,000 iPhones sold over the weekend? (Update: 1 million)

The iPhone 3G S had a solid start this week by anyone’s standards.  Gene Munster and his crew were out trying to put demographic numbers on the long lines of people waiting for iPhones.  According to Apple 2.0, this is what he came up with:

• 750,000 iPhones. Munster estimates that Apple sold about 750,000 iPhones over the three-day weekend, 50% more than his initial prediction (500,000) but 25% less than the 1 million iPhone 3Gs Apple sold on launch last July. It took Apple 74 days to sell 1 million first-generation iPhone and three days to sell 1 million units of the iPhone 3G.
• Shrinking windfall. Among the 256 customers surveyed, 28% were switching carriers to AT&T, down from 38% last year and 52% in 2007. AT&T’s iPhone windfall is shrinking.
• Brand loyalty. 56% were upgrading from an old iPhone, up from 38% last year. “We believe this shows Apple is developing brand loyalty not enjoyed by other mobile phone makers,” Munster writes.
• 16GB sweet spot. 43% bought the high-end 32GB iPhone 3G S, down from the 66% who bought the high-capacity model (16GB) last year and the 95% who chose 8GB over the 4GB when the first iPhone went on sale.
• Business users. Among customers buying their first iPhone, 12% were switching from a Research in Motion BlackBerry, up from 6% last year. This, says Munster, “may indicate the company is making headway among business users slowly adopting the iPhone platform for corporate use.”

Update: Apple, this morning said in a PR Release that it had, in fact, sold over 1 million iPhones over the three day period.