We live a few miles south of the Burren, in County Clare - this weekend sees the end of the annual Matchmaking Festival at Lisdoonvarna, where elderly farmers used to go to find young wives to be their housekeepers (among other things!)
This is one of the stories connected with the custom (also told in the Appalachians, by the way)

An old bachelor farmer working his farm in one of the most remote areas of the Burren, used to go regularly into Lisdoon to stock up on supplies when they ran out
One Saturday he set out into town on his donkey and cart to stock up for the Autumn, forgetting that the Matchmaking was still in fill spring
Down the long narrow rock road he went until he arrived in the town; he was a little puzzled to see the hundreds of people crowding the streets of the normally quiet towneen
He bought what he needed, carried them out and piled them high onto the back of the cart.
As the poor beast dragged the overloaded cart out of town, the farmer spotted a young one standing on the side of the street looking to be hired for the season - the farmer, remembering what time of year it was,strode over to her and made his bargain - the two walked back to the cart and he lifted up to sit on the pile of goods
They drove along the Ennistymon Road until they came to the farmer's turn-off and began to make their way up the steep, stony track - a half mile into the journey, the donkey stumbled - "That's one" said the farmer - the girl sat there bemused, but said nothing.
A mile further the poor beast stumbled again: "That's two" said the farmer - again, the woman, held her peace.
A mile further the animal stumbled a third time.
"That's three" said the farmer and walked around the back of the cart, scrabbled under the goods and pulled out a large, thick blackthorn stick; walking around to the front, he struck the donkey a mighty blow between the eyes, killing it stone dead
Well - your wan was horrified - she leapt down off the cart and screamed at the man: "Why did you do that - it wan't the poor creature's fault you overloaded the cart - what are we going to do now; we're nowhere near a house, it's getting cold and dark, its beginning to rain and I only have light shoes..... how are we going to get home?
The farmer looked at her coldly and said quietly - "That's one"
Jim Carroll