It is a horrible industry, but the margin is as low as 2% on their books.Top 5 UK betting companies revenue 2019:
Entain PLC (Ladbrokes, Coral, Gala etc) £3.6 billion
Bet365 £2.98 billion
Flutter Entertainment (Paddy Power, Betfair etc) £2.14 billion
William Hill £1.6 billion
888 Holdings £560 million
They really are evil parasitic scum whose continued existence shows how far we are from a rational and humane society.
there is a lot of money going through bettors who are playing the markets rather than gambling. If you are arbing dutching or matching you can turn over your betting money several times in a day.