I think, it's meant like this:

If the lottery gets too big, then it's an investment = if your gambling gets to big, then it's an investment. If you do big gambling, then it's an investment. The law of bigger figures :) the often you try, the higher the chances (whereas the chances stay unchanged here)

It's not about the lottery and it's pots itself (like euro jackpot, USA Powerball.. etc)