It might make a little more sense with the numbers. WinFall was a typical lottery game where you choose 6 of 46 numbers[1]. As with most lottery games, there is a jackpot payout but there are also payouts for matching 3, 4, and 5 of the numbers. The odds breakdown goes like this[2]:

  Result | Odds
  -------------
  6 of 6 | 1 in 9,366,819
  5 of 6 | 1 in 39028.41
  4 of 6 | 1 in 800.58
  3 of 6 | 1 in 47.40
  2 of 6 | 1 in 6.83

The issue with WinFall is that when the jackpot increased past $5MM, the expected value of the non-jackpot winnings becomes favorable to the player. I.e. a 5-of-6 matching ticket might normally yield $4,000 but may yield >$20,000 for a "Roll-down" game. So if you go out and buy 200,000 tickets for the roll-down game (assuming all tickets are different and numbers are selected at random), you should expect to have 5 5-of-6 tickets, 250 4-of-6 tickets, 4,219 3-of-6 tickets, and 29,283 2-of-6 tickets. The combined winnings of all of those tickets makes it profitable.

[1]: https://www.mass.gov/files/documents/2016/08/vv/lottery-cash...

[2]: https://en.wikipedia.org/wiki/Lottery_mathematics