the federal laws on sports betting were ruled unconstitutional by the supreme court in 2018 (and took a hatchet to the federal ban on gambling), making it become something that could use the banking system and access traditional forms of credit/capital. that means profits, proceeds and revenues from sports betting no longer operates as a physical cash business with safes, guards, asset forfeiture in the informal economy. so basically, 99% of the labor, risk and material costs associated with book making vanished, because it can all be handled by an algo and an online merchant account.

now they can take some tiny fraction of the revenues and put them into advertising and now inducements and enticements to gamble on anything are on every screen several times an hour.

as someone who does not gamble, it has been insane how meteoric the rise of gambling has been. every "casual" sports gambler i've ever known has always had the same rationale as to why they do it: "the games are boring and this makes them interesting." as an aside, it's kinda wild how much of our trillion dollar entertainment industry requires meta-gaming added to it (fantasy football, gambling) to get people to continue watching it.

EDIT here's an article from 2021 to add some context:

https://www.usatoday.com/in-depth/graphics/2021/09/09/online-sports-gambling-good-bet-industry-continue-winning-ways/5686836001/

Goldman Sachs projects that online sports betting could grow 40% annually over the next decade, and investors have taken note. The BETZ exchange-traded fund, which includes several online gaming companies, has grown more than twice as fast as the S&P 500 since the ETF's inception in June 2020.

it's basically a gold rush situation. i would expect it to create a bubble, but gambling gets even crazier when the economy contracts and now that people can run up credit card debt with gambling who knows how deep this well goes.