I haven't tried the service since I'm not in the coverage area but it would be nice if you could take a pic of a grocery reciept and let it automatically import an order
That's a difficult problem to solve. Nevermind the OCR issues surrounding different store's receipts, the line item descriptions are so varied and atrocious, it would be a very large undertaking to match them against Instacart's existing product database.
Good idea, just hard to execute, and I'm not sure it would have a sufficient payoff to be worth it.