The ultimate dream for many a pony mad child was getting a pony, and some lucky souls achieved it by winning one. Judith M Berrisford's fictional Jackie did it in Jackie Won a Pony by winning a competition in Horseshoes Magazine.
People did it in real life too: Pony Magazine, in its earliest days, ran Win a Pony competitions, which required some dedication. It wasn't a question of whipping a quick essay off or doing a few questions: you had to enter twelve separate competitions over a year. Here's one from September 1950, in which you had to complete the story by filling in the blanks with names from the list of well known horses and ponies supplied.
This is the winner (or at least I assume it is: the competition presumably ran into 1951). Carolyn Brown won Mr Murphy, and this is a photograph of them, reunited, in 1958.
Dragon's Win a Pony competition in 1966 was rather less taxing: matching attributes to characters was all that was required. The competition was held to publicise their launch, with Mary O'Hara's My Friend Flicka being part of the first tranche of books. There are still lots of those two part Flickas about. I wonder if many of them were bought so their owner could have a go at winning a pony. I bet they were. I was only 4 at the time, so the competition passed me by (though I was already pony mad. There was a riding school at the end of our garden. Despite being comprehensively bitten by one pony, nothing stopped me from spending hours hanging over the fence at the end of the garden, stroking whatever pony would wander up to me.)