-Uses it's own special kind of barcode
-Doesn't let people compare prices locally
-Is simply a barcode-encoded URL
/sarcasm
Cuecat was a device that was about a decade too soon. We needed ubiquitous mobile computing (not just mobile phones, you see) before something like this could truly come into its own.
I saw the special barcode for the cuecat in the wikipedia article but I don't remember it being restricted to only those types of barcodes. I'm pretty sure it worked for any barcode. It also says they were trying to avoid patent infringement. I suppose that patent has expired (cuecat was 10years ago! wow), but now that redlaser is worth //evil-voice One Million Dollars!, they may have to pay the piper.
So again - you think it's economical to invest 2k into a device that lets me save 40 cents on Ketchup?
I don't understand your assumption that users are buying iPhones only to use this app and not, say, to also make phone calls and browse the web. In the past, people bought iPhones even when this app was not available, and they paid more.
You should be asking instead if it's economical to invest $2 into an app to save 40 cents on ketchup. (And, if you plan to make more than five such purchases, the answer is "yes".)
-Uses it's own special kind of barcode -Doesn't let people compare prices locally -Is simply a barcode-encoded URL
/sarcasm
Cuecat was a device that was about a decade too soon. We needed ubiquitous mobile computing (not just mobile phones, you see) before something like this could truly come into its own.