I remember seeing an interview with a flambouyant Bookie called John banks I think it was around the 80's, anyway his quotable quote was that when he goes to the races with 1000 quid he "hopes" to win 100quid , wheras the punters go to the course with 100 quid and expects to win 1000quid.

Massive empires have been built with a house advantage (guaranteed) with only around 2%-3%.

If one can find a method that gives us 'that' guaranteed permanently then, Carribean here we come!