- Insurance prevents financial catastrophe by aggregating risk, yet it is nothing more than wagering you'll get into trouble.
- Market liquidity is provided by people willing to bet on price developments, which smoothes out fluctuations in availability.
- Large infrastructure projects and charity donations been financed through lotteries -- it's a way to raise money without a guarantee of return.
- If you want to sell something which a single buyer cannot afford, and it is difficult to share, it can be sold through a lottery which lets buyers buy a ticket's expected value rather than the full cost of the thing.
These benefits still exist when unregulated, but of course it seems to work even better under the appropriate regulation.
