A boost is a multiplier of your transaction round up. We currently offer a 2x, 3x, or 4x. Example: If your coffee is $3.50, Bits rounds up the extra $0.50, you can now boost this round up by 2x ($0.50 x 2 = $1.00), 3x ($0.50 x 3 = $1.50), or 4x ($0.50 x 4 = $2.00).