(a) The term "employment" shall not include services performed as a real estate salesman to the extent that such services are compensated for by commission.(b) After December 31, 1986, the term "employment" shall not include services performed as a direct seller engaged in the trade or business of selling, or soliciting the sale of, consumer products to any buyer on a buy-sell basis, a deposit-commission basis, or any similar basis in the home or in an establishment other than a permanent retail establishment, if:(1) Substantially all the remuneration, whether or not paid in cash, for the performance of such services is directly related to sales or other output, including the performance of services, rather than to the number of hours worked; and(2) The services performed by the person are performed pursuant to a written contract between such person and the person for whom the services are performed, and such contract provides that the person will not be treated as an employee with respect to such services for federal tax purposes.