The stores generate over $100k per employee per quarter. In 2010, revenue was $481,000 per employee. This year the average is around $320k excluding the fourth quarter. In 2009 the average revenue for the technology sector was $388k/yr. A retailer like JC Penney generates about $124k of revenue per year per employee.
The revenue per visit is around $45. There are well over 250 million visits per year (222 million for first three quarters of 2011).
The number of employees has grown in proportion to the number of visits. There is one employee for every 2,500 visits/quarter. The following chart shows the relationship between retail personnel and store visitors on a quarterly basis.
Assuming an employee works for 360 hours per quarter, the average employee sees 6 visitors per hour or one every 10 minutes.
As that visitor generates more than $45 of revenue, an Apple store employee creates sales at the rate of about $278/hour.