It annoys me on the Celebrity one when they name a massive national charity where the money will be just a drop in the ocean rather than a local one where it’ll make a huge difference. It just means they haven’t thought at all.
I don't think it happens all the time, especially when they choose little local charities, but I read that it often works the opposite way around to what you'd think.
Instead of the show approaching a celebrity and then the celebrity choosing their favourite charity, it seems that big charities will scout out celeb ambassadors (or their agents) and badger them to get on board and then approach the TV companies. They quite probably petition to secure places in advance, like with the London Marathon, and then find the biggest celeb they can to take the slot - wouldn't surprise me at all.
I wonder if, for shows like The Chase, they use algorithms to crunch all of the statistics and order 'their' celeb as to which 'offer' level to go for.
We watch, thinking that a charity will be watching too and be delighted upon discovering that a big donation is coming their way out of the blue when, in reality, they've set it up all along, have their targets ready and are pressuring the celeb to come up with the goods and not disappoint them! "Hmm, well that was very disappointing, wasn't it, Gemma. All those poor, cold, shivering hedgehogs who will go hungry, now, eh? Rachel Riley wouldn't have let them down, would she.... just saying...."