I wouldn't say invented so much as 'foresaw the large opportunity'. It popped up on Techcrunch a lot before GroupOn, ie. how is it that the $170B local ad mark

I wouldn't say invented so much as 'foresaw the large opportunity'. It popped up on Techcrunch a lot before GroupOn, ie. how is it that the $170B local ad market has been left untouched by the web?