By Katie Marsal

Published: 07:00 PM EST

A series of changes to Apple's retail-based One-to-One training service slated to go into effect on Tuesday may have been driven in part by the popularity of the program, which is rapidly swelling to complex proportions.

In a discussion with USAToday last week, Apple retail chief Ron Johnson broke word of the upcoming changes, most notable of which is a new restriction on who can purchase a subscription to the personal training service.

Currently, anyone with $99 to spare can sign up for a year-long One-to-One membership. But beginning Tuesday, only those customers who purchase a new Mac from an Apple-owned retail store or the company's online store will be eligible for the program.

Existing One-to-One members and Apple retail insiders commenting on the matter over at ifoAppleStore note that the program has been a resounding success with one exception: recently it's become increasingly difficult for members to secure reservations for training sessions that aren't held during the middle of the work day.

Apple's roughly 250 retail stores already service more than 500,000 One-to-One members, who last quarter combined to sign up for more than 644,000 personal training sessions. Add to that research which reportedly shows 50% of One-to-One members sign up for the service after purchasing their Macs somewhere else, and Apple may have had no option but to restructure the program to better new in-store customers.

As one commenter points out, the changes to One-to-One are part of a broader strategic shift underway at Apple retail stores that will focus on customer service and "Creating Owners." With Apple seeing steep price competition from its growing fleet of authorized Mac resellers, One-to-One's new exclusivity will present novice or new-to-Mac users with a compelling reason to buy direct from the company if there's an Apple store close by.

The new One-to-One will bundle personal setup and data transfer services that were previously part of Apple's complimentary "Standard Care" treatment for each new Mac buyer. This initiation service will reportedly include an invitation for new Mac buyers to return the next day at 5:00 p.m. or later to "meet" their new Mac in an inaugural one hour training session.

A handful of other changes are also in store for Tuesday's service relaunch. First, tipsters tell AppleInsider that members will now be able to register for more than one session each week, given that each new session is registered after the conclusion of the previous session. Apple stores will also host a new 3-hour "Project" session each day for up to six members at a time, headed by a Trainer who'll be available for questions.

Meanwhile, ifoAppleStore notes that Apple will also be adding new Web resources for One-to-One members, including a personalized on-line account that lets them reserve sessions, review session notes, complete on-line training, and view projects from their own or others’ training sessions. The blog adds, however, that the new restrictions mean that One-to-One memberships can no longer be given as gifts or used to bait potential switchers to the Mac platform.

As part of its retail reorganization, Apple also plans to retrofit 40 percent of its stores with Genius Bar customer service stations that can accommodate 50 percent more customers. It'll also be rolling out new display tables capable of showcasing twice as many Macs.