[the-rc]

I would have guessed that the surge had something to do with faster payments, namely contactless and the wireless terminals. In a way, it's even broader than that: if you order for pick up and prepay, payment is pretty much out of the picture entirely, replaced by just verifying that you are getting the right order. Then you're avoiding the productivity losses in serving the dishes, washing the plates, etc.

[relaxing]

The correct answer is right there in the abstract. It’s not even 200 words. You don’t even have to read tfa.

[the-rc]

True... I didn't make clear that I had tried to take a wild guess after reading only the first sentence in the abstract.

[muirbot]

I think that’s pretty clear