What sparks an iPhone upgrade? It might be a revolutionary design change like flat edges to curves or the introduction of Face ID. More likely, it's a photographic feature like a decent telephoto lens or when Portrait Mode first arrived and transformed every new iPhone 7 Plus into a virtual pro-level camera.
Sometimes, it's not so much the features alone that inspire an upgrade – it's the FOMO. I know that anyone who saw my Portrait Mode images from that iPhone 7 Plus was so agog that they looked dismissively at their likely iPhone 4s or 5s and almost immediately began researching the trade-in prospects and costs for that new device.
