What is the advantage of buying an expensive index ETF for the S&P 500 compared to a cheap one?

Aren't they tracking the same thing? (maybe a bit different in percentages allocated). So wouldn't you be able to make more off buying the cheaper one? I'm asking because people always recommend $VOO or $IVV.

Submitted January 05, 2017 at 08:35AM by sorryforhating http://ift.tt/2iLUzpR