On Sunday night the Facebook page was set up and by the time he had gone to bed there were 200 likes. The interest has grown and yesterday there were over 1200 likes. The first clue was posted on Monday but with no indication of how much money was at stake.
Kim Hayes, a 22-year-old nurse, and Sarah Crosby, a 21-year-old mum, were determined to find the cash and were not aware of each other's tenacious pursuit.
Miss Crosby's search took her to Tutukaka, Parua Bay and around Whangarei. As soon as the first clue appeared on the social media site, Miss Hayes was out and sure the treasure was somewhere around Riverside Drive "near the shops". However neither was successful and when Ms Hayes put out a call on the page to create an "alliance", Miss Crosby immediately answered.
They met up on Tuesday and together they went through their individual paper work and discussed theories about where the money was hidden. They trawled Port Rd but settled on Riverside Drive as a prime spot. Hours after they began, they were at Kissing Pt, searching below a massive propeller. They were unsuccessful and went home - but only after Miss Hayes had conducted a final search using a torch.
A note by the organiser confirming the cache had not been found yesterday spurred Miss Hayes back into action and by 8am she returned to Kissing Pt and found the money beneath the propeller.
"Another lady had turned up just as I opened the small bag, saw the $100 and the instructions. It was so exciting," she said.
"It wasn't ever about the money or how much money you won. The positive thing I have heard from people was that it was a great bonding experience. Families were out there, mums and daughters were having a go and friends. It was all good, harmless fun and I'd do it again."
And, true to her word, she will give half the stash to her new friend, Miss Crosby, who was ecstatic about the find.
"Kim let me know straight away that she had found the money. The whole thing was amazing. It wasn't just about the money, it was about exploring and making another friend."
The anonymous money donor said the first hunt had been a good experiment.
"I can't solve the world's problems but I can create a bit of light-hearted fun. I haven't got $100 a week to give away so we are now planning how we move forward ... watch this space."
Similar treasure hunts are appearing in other parts of the world, including Nigeria, Netherlands, UK, the US, India and Hong Kong.