Check out this math.
Let's say you place 5 bets.
Each bet is -110 odds and you spend $100 on each bet.
So, your total investment is $500.
If you win all 5 bets, you will get a max pay of $954.55
Subtract the $500 investment.
Your total profit is $454.55
However, if you lose ONLY TWO of those bets...
Your total profit is now $72.73
How quickly the money disappears.