By Prince McLean

Published: 02:00 PM EST

The average Apple retail store sells as many iPhones in a single day as most AT&T retail stores sell in an entire week, say a team of analysts for investment research firm Piper Jaffray.

In their latest round of channel checks, Sr. Analyst Gene Munster and fellow Wireless Analyst Mike Walkley spent a considerable amount of time counting the number of iPhones leaving Apple and AT&T retail stores across the country.

Munster, who in a research note Tuesday said he spent 50 total hours at various Apple retail stores counting sales of the iPhone in two-hour intervals, reported that each Apple retail store sells an average of 21 iPhones per day. Paling in comparison were AT&T's stores which, according to Walkley's checks, sold just 21 iPhones per week.

Based on the pair's findings, Munster said Apple will likely hit its stated sales goal of 730,000 iPhones during the current September quarter ending the 29th, and may even sell as many as 804,000 units.

"We are in a unique position with iPhone channel checks, as the phone is only being sold in the U.S. at Apple and AT&T retail outlets, and Apple's online store," Munster explained. "Thus, we believe our checks accurately capture the market trends in the quarter."

For his part, Munster said his checks were roughly weighted between Apple's flagship stores (on the east and west coasts) and regular stores (in the Midwest). Given the average units sold in each two-hour period, he then extrapolated to a daily count using the average 11-hour retail day (10 a.m. to 9 p.m.).

Finally, the analyst took a weighted daily average for flagship stores and regular stores -- using 15 flagships (8 percent) and the remaining regular-sized stores (92 percent) -- for a final number of 21 iPhones per day at the average Apple store.

Using the same weighted average of flagship stores and regular stores, Munster -- who was also tracking Mac sales -- found that the average Apple retail store sells 55 Macs per day.

"This number implies 866,000 units from Apple retail stores; assuming another 17.4 percent of total Mac sales come from the Apple online store, and another 47 percent are sold through indirect channels, our estimates now suggest 2.0 million units for the September quarter," he wrote. "We note that this data should be supplemented with additional data, as the Mac channel is not as clean as the current iPhone channel, and we have no data with which we can compare our checks."

Munster maintained his Outperform rating on shares of Apple with a 12-month price target of $211 per share.