Retailers and affiliates doing business online are unable to tap into markets outside the U.S. because of logistical problems or the expenses associated with shipping, according to a study cited by Internet Retailer.

The World Market Express survey of attendees at the recent retail e-commerce affiliate conference (Affiliate Summit West) found that while most - 87 percent - would like to be able to business outside the United States, there are problems and costs associated with doing so. Some 34 percent of those surveyed cited the expense of international shipping as the main reason they could not satisfy such orders.

Also, 29 percent said all their business was in the U.S., and 50 percent said international sales accounted for 10 percent or less of their business. Some 21 percent said the lack of internal systems for handling such orders was stopping them.

Some also said that affiliate programs often referred international business that could not be satisfied, rendering that referral essentially useless.

The U.K. is the largest non-US market among those who do satisfy overseas orders, with 28 percent of e-tailers saying they do business there. Canada was second, with 25 percent. Australia was third with 11 percent.