Section 30. Whoever, in connection with the sale of any article or any merchandise whatsoever, sells, gives or delivers any trading stamps, checks, coupons or similar devices to be exchanged for, or to be redeemed by the giving of, any indefinite or undescribed article, the nature and value of which are not stated, or to be exchanged for, or to be redeemed by the giving of, any article not distinctly bargained for at the time when such trading stamps or other devices as aforesaid were sold, given or delivered, shall be punished by a fine of not less than ten nor more than fifty dollars.