"People don't believe that it's free, and that they can ask as many questions as they like," said Jacy Escoffier, one of the six "Creatives" staffing the Studio in the San Francisco store.

Johnson won't say how much Apple is investing in the Studios and in hiring Creatives, other than to describe the amount as "appropriate." Apple stores had sales of $1.1 billion, or 16.4 percent of the company's total revenue, in the first half of its fiscal year.

When Apple opened its first retail stores in Glendale, Calif., and in Tysons Corner, Va., in 2001, it introduced its Genius Bars, where staff members gave advice on technical issues.

But the "Geniuses" were increasingly fielding questions about creative products that were beyond their expertise. So Apple set up Studios and hired Creatives.

"When you have access to someone who's done it before, they can quickly guide you in the direction to make what seems difficult easy," Johnson said.

"We thought: Wouldn't it be great to put in our stores real filmmakers, real musicians, real photographers, real videographers ... and let them provide face-to-face support."