Many donation sites give donors the option to increase their gift by the amount of the processing fee. When our donors learn of our transaction fees, they become discouraged about making a gift by credit card and send a check instead. Some have expressed a desire to pay the the transaction fee, but manually calculating it is a hassle. Still others have have become interested once we made the suggestion to them that they could add it to their gift, but the webpage could prompt them with a checkbox without us having to get involved.