If they're doing something really clever to read these barcodes it makes some sense to not just give it away. The Apache licence does give them that option.

There are many surprising things about RedLaser's success, but technology isn't one of them. I agree with OP that apparent violations of licensing (access to Amazon.com via mobile is not allowed) are surprising. Most surprising to me is how well RedLaser has sold given that barcode scanning was antiquated over a year ago by products like SnapTell. Why scan a UPC code when you can just take a picture of the cover of a book and have the product found just as fast, with as good or better accuracy? No matter if your photo is blurry, or badly lit, or out of focus, or only grabs a part of the book's cover...

Surely the error rate of that compared to bar codes is much higher. For common products Im sure it works just as well but bar code scanning doesn't degrade for edge cases in the same way.

(Disclosure: I have nothing whatsoever to do with SnapTell, but I have been consistently impressed with the technology.)

"WARNING: 10/14/2009 The RedLaser SDK currently uses an unpublished function to access video frames. Very recently, others have indicated that this will likely lead to rejection of any application using this function, including any application with the RedLaser SDK. We are working hard to find a solution, as we believe there is great potential for this technology on the iPhone. Please take this into account when considering use of the RedLaser SDK."

So they probably analyze a lot of different video frames before finding an accurate one.

The main camera app does this too.