A downline builder holds a list of programs for you to join. The idea behind it is that you will join listed programs (that your sponsor will get credit for you as a referral in all of the programs listed). Then you will have to recruit your own referrals to fill your downline and and get credit for them as referrals in many of the programs they join under you and so on. Downline builders can be quite effective tools, when you understand the concept. When done right it will surely pay off, just make sure the DB you join has a worthwhile program inventory to suit your needs. When those requirements and qualities are met, you are good to go and the outcome is up to you.