Tomorrow's lotto jackpot offers (slightly) positive EV

Many mathematically unbeatable games of chance (lotto, progressive slots, video poker, blackjack, etc.) can become +EV under the right circumstances. That said, the analysis is not quite as simple as quoted:

"Tomorrow's Mega Millions jackpot is $208 million; the odds of winning are 1 in 176 million ∴ the EV for each $1 ticket is positive 18¢!"

...because (as the later tweets point out) you don't know how many tickets will be sold, and the math needs to take into account the possibility of "split jackpots" in which two or more people win the big prize(s).

A more rigorous analysis of "when is it rational to purchase a lotto ticket" in the general case can be found here:

http://psyllogism.wikidot.com/articles:lottery