We are more distractible when reading on digitsl devices though. Perhaps with the exception of dedicated ebook readers.

In addition to fhat I wonder if eInk and actual paper are more conducive to prolonged reading as well, less eye strain

There are a few restaurants I have been to in the US that actually pay living wages and say tipping is optional. When the service is really good and you insist you want to tip they are generally over the moon.