Which product development innovation most significantly expanded the amateur astronomy market in the 2010s?

The astronomy industry has seen remarkable technological advancements in recent years, not just in observational equipment but also in how astronomy products are marketed and developed for both professional and consumer markets. This trivia question focuses on a significant product development strategy that revolutionized how astronomy equipment reaches enthusiasts.

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Computer-guided 'GoTo' telescope mounts with smartphone integration
Subscription-based access to remote observatories
Mass production of titanium-frame telescopes
3D-printed telescope components sold as DIY kits