Let's say there was an product that you were willing to pay $10 for, but someone was selling it for only $6. By purchasing the product you get $4 worth of consumer surplus.
In general you probably get at least a bit of consumer surplus for everything you buy. The more surplus, the easier the decision to purchase (Of couse I would like to buy that brand new MacBook Pro for 10 bucks, thank you good sir!).
@ half the price and twice the customers you have all the customers who would have bought at the higher price "earning" whatever their surplus would have been + the (half) price - . On top of that you have all of the new customers "earning" a surplus beteen zero and the lower price.
In general you probably get at least a bit of consumer surplus for everything you buy. The more surplus, the easier the decision to purchase (Of couse I would like to buy that brand new MacBook Pro for 10 bucks, thank you good sir!).