They say less is more, but not when it comes to warehouse shopping. The point of buying in bulk is that more is less, as in less money per unit. Rather than spending $2 on a bottle of water, the cost is greatly reduced when you buy in bulk.

"You're going to have to buy a 12-pack of it, but at the same time, it's only 80 cents a bottle, so buying more saves you money,” says Chieh Huang, co-founder and CEO of Boxed.

Boxed is a company that offers wholesale by mail. Huang started the company in his New Jersey garage two and a half years ago.  Today, they have multiple fulfillment centers across the US and millions of customers using the app to order bulk items. The bulkier, the better.

“The items that do the best are the ones that people don't want to carry home,” Huang says. “So toilet paper, paper towels, the large 120-ounce Tide detergent.”

When it comes to buying big online, he says a bulk of his customers is under the age of 45. Half of them have children and half do not. Half live in cities and half in the suburbs. However, he says they have one thing in common.

"Most are incredibly busy and 100 percent of those folks value their time,” Huang says. “It definitely is not for everyone, but it is for a large part of the population."

Of course, there are some downsides to shopping in quantity. On perishable products, you need to pay attention to expiration dates. Then there's the question of space. Assuming you don't live in a warehouse, where do you store all those big boxes? Huang says, given the chance to save money, people will find a way.

 "We get pictures all the time on social media to see how people are tetris-ing these things into their closet,” Huang says. “So if you don't have a lot of time and you want to save a little bit of money, it's interesting how much closet space you can find to store like 10 rolls of toilet paper."