128 BTC is a Peer-to-Peer Multilevel Structure where you can donate to each other and build a Bitcoin empire. There are six levels in it and it works in the following way as show below.
In the level 1, when you donate 0.0005 Bitcoin, you get 0.0010 Bitcoins when 2 people donates.
In the level 2, when you donate 0.00075 Bitcoin, you get 0.0030 Bitcoins when 4 people donates.
In the level 3, when you donate 0.0020 Bitcoin, you get 0.016 Bitcoins when 8 people donates.
In the level 4, when you donate 0.010 Bitcoin, you get 0.16 Bitcoins when 16 people donates.
In the level 5, when you donate 0.10 Bitcoin, you get 3.20 Bitcoins when 32 people donates.
In the level 6, when you donate 2 Bitcoins, you get 128 Bitcoins when 64 people donates.