Specific to speeding lines, especially in cities such as New York the use of QR codes might be employed as they have in Asia and EU countries, this since they can hold the item/s SKU, Price, inventory, etc.. In addition, it’s yet another great way to build on a loyalty program.
Create within the existing IOS and Android Apps a section for a customized QR generator.
When Sally J consumer enters a store, For example; Union Square North, NYC where it’s not atypical to see twenty or more people on line – she fires up her Starbuck App, opens the section where she had setup a QR code for her favorite drink, a Tall Mocha. When Sally sees the line see steps to the scanner by the door, or the one the roaming Starbucks employee has in their hand and swipes to register her drink order.
On the back-end, the system would register her order at an LC-Display over the Barista station, this along with her name: Sally J. Since the payment would be auto-deducted from her app, Sally steps to the pick-up area avoiding the register altogether. You might want to consider a separate Barista just for these e-Drink buyers, this since will not drain resource time from your main Barista’s, think the upgrade line at the airport for business-class.