Two sites I have made profit on and two sites I have had losses from.
See https://ttlc.intuit.com/community/taxes/discussion/schedule-c-for-gambling-income-where-to-show-loss/00/164024
See also https://proconnect.intuit.com/taxprocenter/tax-law-and-news/professional-or-casual-gambler-how-to-help-your-clients-play-their-cards-right/