Is a National Marketing Company considered Direct Sales?

Typically, yes.  According to IRS Publication 334, 

"You are a direct seller if you meet all the following conditions.

1. You are engaged in one of the following trades or businesses.

• Selling or soliciting the sale of consumer products either in a home or other place that is not a permanent retail establishment, or to any buyer on a buy-sell basis or a deposit-commission basis for resale in a home or other place of business that is not a permanent retail establishment.
• Delivering or distributing newspapers or shopping news (including any services directly related to that trade or business).

2. Substantially all your pay (whether paid in cash or not) for services described above is directly related to sales or other output (including performance of services) rather than to the number of hours worked.

3. Your services are performed under a written contract between you and the person for whom you perform the services, and the contract provides that you will not be treated as an employee for federal tax purposes."

The direct seller is self-employed and subject to self-employment taxes.  

In TurboTax the direct seller will use the "Self-employment" topic to enter income and expenses for the sales job.