The term "employment agent" shall mean and include all persons, firms, corporations or associations, excepting municipal corporations, church and charitable associations, which furnish, to persons seeking employment, information enabling or tending to enable such persons to secure the same, or which furnish, to employers seeking laborers or help of any kind, information enabling or tending to enable such employers to secure such help, or shall keep a register of persons seeking employment or help as aforesaid, whether such agents conduct their operations in a fixed place of business, on the streets, or as transients, and also whether such operations constitute the principal business of such agents or only as a side line or incidental to other business.