It's less expensive... and not because it's poorer quality
Bottling is costly, as it turns out... but what about boxing? In addition to being totally badass when done by Muhammad Ali, it’s also much less expensive when applied to wine. The plastic bags inside boxes of wine are often vacuum-sealed, and the boxes themselves are made out of cardboard, which is extremely efficient to produce (and transport) when compared to the glass used for bottles.
“In theory, these savings can be passed along to the thirsty consumer,” says Lipp. In this case, the consumer can afford to be a little thirstier -- boxes of wine typically contain around four times as much wine as bottles, as well.