In a binary MLM plan, each distributor has exactly two direct positions — a left leg and a right leg. Once both positions are filled by two directly sponsored members, the third recruit has nowhere to go in the direct slots. This is where spillover occurs.
Spillover is the automatic placement of a new recruit into the next available open slot below an already-filled position. The system follows a configured placement algorithm (typically breadth-first) to find the optimal open slot in the same leg direction the sponsor intended.
The key benefit of spillover is that it creates a genuine team dynamic: when a top-performing leader recruits heavily, their overflow placements directly benefit the distributors below them — filling open positions in downline members' trees, adding BV to their legs, and potentially triggering pairing bonuses for people who didn't personally recruit those new members.