Unexpectedly high shipping fees are the primary reason why consumers abandon online purchases, according to a survey from PayPal.

The study also found that many consumers abandon their purchases for payment-related reasons. Of those surveyed, more than one in five shoppers didn't complete purchases because their preferred payment option was not offered on the merchant's Web site.

In addition, the survey found that:

*Sixteen percent of respondents didn't pay for items because they could not contact customer support to answer questions.

* Fourteen percent of shoppers didn't pay for items because they forgot their usernames and passwords for their store accounts created with the merchants.