>>remram+zi
In the US advertising is considered a business expense. So we equate it with investing in infrastructure or research, both of which reasonably would be subtracted from your revenue to determine your tax burden.
>>hinkle+Zw1
Payroll taxes are paid into social security as an insurance payment. It is a percentage of what you pay the employee. Some might say that it is part of the employees pay.
I don't know what that has to do with taxing marketing spend.