Online sports betting has exploded into a $166 billion-a-year business, and the damage is landing hardest on people who can least afford it.

• Americans bet $166 billion on sports last year, up from under $7 billion in 2018, with nearly all of it placed on phones.
• DraftKings built a machine-learning model to spot which customers were most likely to respond to promotions and lose the most money, then targeted them.
• Just 5% of bettors absorb 95% of all betting losses, and those are the people the apps chase hardest with VIP perks and luxury suites.
• Diagnosed gambling disorders are up 61% in states that legalized, and those states have seen a 25% rise in bankruptcies and credit card defaults.
• Half of sports bettors say they have placed bets to try to pay bills, and a fifth have gambled to cover rent or a mortgage.

Outlook: With $72 million already spent lobbying ahead of the midterms and the NFL renewing its deals with FanDuel and DraftKings, no meaningful crackdown looks likely.