There are many measures you can use to gauge the influence of the iPhone, a gadget that has changed human behavior in ways that few other things could. But a good place to start is by looking at products that the do-it-all smartphone has elbowed aside en route to where it is now (which is everywhere).
The list of maligned objects is long. When was the last time you used an MP3 player or held a calculator? What about a physical map? Or a BlackBerry? Do BlackBerrys even exist anymore?
There might, however, be no better example than the camera, which has suffered mightily since the iPhone was introduced almost 10 years ago.
For a while, it was one big camera party. Sales grew modestly but steadily until the late 1990s. Then digital cameras were introduced, and demand soared. Thereafter, the industry grew quickly. That is, until 2007, when Apple launched the first-generation iPhone.
What happened next is pretty self-explanatory.
The biggest hit has been to point-and-shoot cameras. Sales of the lower-quality, fixed-lens, hand-held devices way too many people used to tie to their wrists have fallen off a cliff since the iPhone's introduction. And few no one expects them to climb back up.
But the iPhone - or, really, smartphones in general - seems to be proving a bit of a thorn in the side of the higher-end camera market as well.
The number of fancier cameras being purchased each year rose through 2013. Some people, having left their point-and-shoots behind, were probably trading up for better cameras. And those better cameras weren't as expensive as they had been in the past - a slew of more reasonably priced digital SLRs have hit the market over the past 15 years.
It's possible that the dip isn't structural - that it's more of a momentary softening of the market than a sign of long-term replacement. Some, after all, argue vehemently that the two aren't actually all that interchangeable.
Taking photos with smartphones and editing them with apps is like cooking with cheap ingredients and a lot of artificial flavoring.
"Taking photos with smartphones and editing them with apps is like cooking with cheap ingredients and a lot of artificial flavoring," Takafumi Hongo, a Canon spokesman, told the Wall Street Journal in 2013. "Using interchangeable cameras is like slow food cooked with natural, genuine ingredients."
But the rapid adoption of the iPhone - along with the drastic improvement of the iPhone camera - makes it hard to believe that the line isn't beginning to blur, if not considerably, then at least a little bit.