Those "I'm rich" apps basically tested the app store price limit which was set to $9,999 (don't know if it's different now). Brilliant idea really.

I put this in the same category as the "Million dollar homepage" where some guy asked for $1 a pixel and hosted a page with the results. Something smart that if it gets enough attention could make someone good money for not a lot of work. And generally something that will only work once as copycats won't be seen to have the same value.