Simple and probably a stupid question..

I have a small home based advertising business. I plan and purchase TV advertising for other small business owners. When i place an advertising schedule on behalf of a client, I am billed for the airtime. If the gross sales are $1000.00 then I bill the client $1000.00 When I receive the money from the $1000.00 from the client, i deposit the money into my business account and write the media outlet a check for $850.00 (minus the $150 agency discount I receive). The problem is, if you look at my monthly bank deposits it appears that I'm making a lot of money. But in reality I"m only making 15% of my deposits. If I deposit $300,000.00 in reality my income was only $45,000.00 gross.

How do I file this?

do I file gross income $300,000.00
or do I file $45,000.00?
If I file $45,000.00 gross, how do i explain the other $255,000.00 that just passed through my banking account?

Thanks in advance!

Not a single reply?????? Have I stumbled upon a dead forum?