If you are selling advertising, I'm sure that's taxable and your state will want a piece of it.
Plus, any equipment actually owned by the business (IE if you try to use your tax cert in order to not pay sales tax on it), usually has to be declared and can also be taxed after a certain value.
Just a note. Purchase of equipment (in my state anyway) can be bought sales tax exempt only if it is used directly to produce a product and then you need a sales tax permit and file sales tax monthly or quarterly reports.
