A 1993 episode of American sitcom Seinfeld highlighted the potential hazard of double-dipping when George was given a lesson by Timmy on the social etiquette of eating crisps with dip.

‘Double-dipping’, a.k.a. the gig economy’s overachieving cousin, might sound like a grafter’s ticket to a better life, but it’s a very risky move that’s almost guaranteed to wreck your ...