It pretty clearly crossed the spam line for me: The parent specifically pointed out that doctors don't give you the PD to in order to force you to buy glasses from them, but suggests there are other ways to obtain it. Eric replies to talk about how much better their app is than any do-it-yourself PD measurement but does not disclose that their app also doesn't give you the measurements in order to force you to buy glasses from them. I did not find this helpful and it is clearly commercial, since the app has no utility other than to sell you their glasses.