Easier scalable webapps, because it is possible to offload some data crunching from server (paid by us) to client computer (paid by him). Examples? Calculatin

Easier scalable webapps, because it is possible to offload some data crunching from server (paid by us) to client computer (paid by him). Examples? Calculating and matching SURF points on large set of images for image matching, point-of-shot localisation and some more fun and profitable purposes.