NEW YORK (MainStreet) — Online shop owners find they have a problem brick-and-mortar stores don’t see as often – abandoned shopping carts full of goods. The source of the problem at e-checkout seems to boil down to money, whether it’s shipping fees that customers don’t like flung on them at the last minute, the absence of a coupon code, or just plain frustration with the process.

Elissa Spektor, owner of Love & Pieces, an online jewelry boutique, says she was aware that shipping costs at check out were making customers think twice about their purchases, so the online retailer began offering free shipping on items costing more than $100.

"That substantially increased conversions,” Spektor says.

However, Spektor was still seeing a 70% abandoned cart rate.

Until the shipping policy was explicitly posted on every product page, there were still a large percentage of abandoned carts, Spektor says.

“With impulsive purchases, people convince themselves they are willing to spend X on your item and add it to their cart,” Spektor says. When they arrive at the checkout and see that there are shipping charges, most of the time they leave, she says.

“We now try and educate them up front so there are no last minute surprises in the cart,” Spektor says.

“According to Listrak’s Shopping Cart Abandonment Index, which calculates the average shopping cart abandonment rate from a sampling of Internet retailers, the last six months have seen about a 74% rate,” says Sarah Griffis, a digital consultant at LYONSCG, an eCommerce digital agency.

A survey of 500 of American consumers by Offers.com found that 41% of online shoppers said they abandon their shopping carts if the purchase is too expensive, 34% say they leave if they find a lower price and 15% say they leave the website when they can't find a coupon code. The rest who abandon their carts fall into two categories: those who filled them only as a way to check prices and those who leave out of frustration with the checkout process.

Griffis says that online shops “need to simplify their approaches to shopping carts.” She also suggests, like Spektor has found, not to hit customers with unexpected charges at checkout.

“Customers are not pleased to see more costs added on at a later step in the purchasing process, especially after they have already taken the time to fill in personal information and answer other queries,” Griffis says.

Griffis also suggests allowing customers to edit the selections in their cart.

“If users have already reached the checkout page, but then are automatically redirected to the cart page to edit product configuration, there is a greater chance there will be cart abandonment,” Griffis says.

And that’s the last thing retailers want.

—Written by S.Z. Berg for MainStreet