Marketing is a necessary expense in running practically any business and the IRS acknowledges as much. You may run advertisements on or in the Internet, radio, television, magazines, newspapers and similar media to sell your products or services. Marketing costs must be ordinary and necessary business expenses to be deductible.
On top of that, such marketing creates a longterm potential for business and, thus, falls within the ordinary and normal requirements of the tax code. Then again, marketing that is intended to portray your business positively can be deducted. You’d better be deducting said expenses from your gross revenues, as long as your marketing expenses can be reasonably about the promotion of your business.