Those companies which de-emphasize product sales and give awards only for "attracting new members" are quite possibly "pyramid schemes." (In these schemes, products are never really sold to consumers, but rather are just passed along to lower levels of middle-men who can only profit by finding more middlemen below them until the pyramid collapses when there are no more people to be drawn in at the bottom.)
不強調賣產品，光靠「拉人頭」為獎金來源的，則有老鼠會的嫌疑。