Not really a new idea. Bittit has been around for ~4 years doing this. Cool though.
https://bittit.infoIts actually opposite of bittit.Bittit has the image completely revealed ,you just have to pay tips to watch it in high resolution.Op's site pixelate's the entire image and only on tips the parts of it are revealed.Tipper doesn't know the entire image before the maximum amount of tips set is received.