Twiglets are strange, they don't taste particularly nice, but if there's a nearby bowl of them at a party they exert a curious magnetic attraction, and you'll find yourself stuffing them your mouth while thinking these don't taste that good. Then you'll eat some more. You don't know why, but you will. It's a strange compulsion. It's not even just me, I've seen other people doing it. You can see the look the look on their face. Why am I chewing a mouthful of dry twigs? Then they reach down for more. You want to get rid of radioactive waste? Paint it on Twiglets, host a party.
I don't care enough about Marmite to love it or hate it. It's vaguely salty and mostly pointless. If anyone tells you it's full of vitamins, well, yeah, they would. Make sure you love them first.