[r00fus]

Exactly. Which Amazon smiles at currently and encourages through their barcode scanning app (this will require internet access for Dash, though - unless it comes with some variation of whispersync).

[simcop2387]

Says it needs an internet connection, but a cell phone as a hotspot would do that pretty easily.

[chockablock]

Or the dash could have an offline mode where it stores scanned barcodes for later lookup.