To be in brief its because of advertising,motivation and contacts. First of all most of us fear to invest our money in online. very few affiliates who are highly motivated and ready to undertake high risk are the ones who was so successful in a few weeks. if you want to be successful in sfi you have to advertise about sfi to all the person you know (choose the right one) and try to acquire as many as psa and motivate them . if you do this money will be coming to your door each month