yes and no.
you place an add, you pay for the add and google makes the money.
if someone sees the add, clicks on it, then buys a service from you, then you make money..
if someone sees your add, clicks on it, thenm doesnt buy from you, you lose money because you paid gogle for that click.
two words:
"Effective Marketing"
if you can tell me how its done let me know!