My main gripe is credit card readers for an entire company. BEST case scenario is this premium costing lightning to 3.5mm dongle works at all. Worst case is it doesn't work.
Do you see the problem?
The best case is new iPhones cost us 30-50 dollars more because we need to get a dongle for each one. The iPhone already carried a premium over the competition, add another 30-50 dollars each and there is no way I could sweet talk our bosses into sticking with iPhones. I could probably get iPhone 6Ss for a while but that will only last so long before people start complaining.
And of course the worst case is it doesn't work at all thus leaving us no choice but to switch.
What good does a high quality DAC do for a credit card reader? Lol
Regardless I'm just going to wait and see what happens before investing too much thought into. Might be a total non issue, or might still have the headphone jack.
Credit card readers simply send the data via an analogue signal over the headphone port, which is then converted via the ADC in the iPhone where the card app software picks up the digital signal. I don't see any reason why this wouldn't happen on the Lightning to 3.5mm adapter exactly the way it does now. Now that I think about it, even the app software should still work, as it's looking for a digital signal coming in off the mic bus. Routing that signal through the Lightning port shouldn't change that. The conversion simply happens inside the adapter, and not the iPhone. Obviously there's still a cost for the adapter, but I don't expect them to cost much more than $20-30 at most. And you don't even need good ones. I'll bet companies like square offer their own low-cost adapters which only have an ADC (and not a DAC) to convert the card info.
I'd say your bigger problem is going to be upgrading to chip readers, whether or not you offer contactless readers as well. And when you do that, you can upgrade to Lightning readers which should work just fine with your Legacy Lightning iPhones as well. Not really seeing a problem here. Might be one of the reasons Apple is doing this now, rather than later after everyone has upgraded their credit card readers for chipped cards, with headphone jack models.