Those iPhone owners who have older models that are overdue or upgrade-eligible for a newer phone may find a reason to move up during an “enormous” event being held later this week at Apple retail stores, according to reports. The promotion, apparently not connected to Apple’s ongoing trade-in program, will be detailed in a report to store management and workers tomorrow. Specifics have not yet been revealed, but eligible owners will be emailed about the promotion.

Apple is planning to hold an “enormous” iPhone-related event in its stores this week in order to boost sales, according to a source with knowledge of the initiative. Beginning May 8th, the source said, Apple will be contacting upgrade-eligible iPhone users with older iPhone models via email to come into their local Apple Store to update to a new iPhone 5s or iPhone 5c… This program blends nicely with Apple’s Apple Store-based iPhone hardware trade-in program, which allows customers to turn-in older iPhone models to purchase a new model at a discounted price. Apple, in recent weeks, has increased the buyback prices for iPhones in its trade-in-program, according to a source.