Apple Inc. is facing an unprecedented challenge: persuading customers to buy its latest iPhones without their biggest new feature.

The new AI iPhone is officially available in Apple stores, hitting shelves in almost 60 countries around the world on Friday morning.

Apple’s annual product launch Monday failed to immediately capture the hearts of investors, as shares of the world’s biggest company slumped during the event largely focusing on previously rolled-out artificial intelligence features coming to iPhones.

Even so, Wall Streremains bullish that Apple can accelerate growth during the all-important holiday season. Analysts estimate that revenue will increase 8% in the December quarter - the best showing for that period since the end of calendar 2021.