paying for delivery with bitcoins the moment you order would be a disaster for the delivery guys...
no more tips...
no more tips...
Luckily not really a thing to tip delivery guys in the UK (yeah yeah, some people do it but it's not mandatory).
Interesting point though, how're beggars and buskers going to get their tips in a bitcoin future?
In a Bitcoin future, the delivery guy will have a QR code on his sleeve/cap. U can instantly tip there. Moreover, tip is not 'mandatory' anywhere !!! If it is mandatory, it is not a tip, it is the price.