You have asked for minimum development work so ...
"Write your email address legibly on a piece of paper and mail it with a US $1 bill to $ADDRESS."
Obviously 1) it will cost people 68¢ for a stamp, 2) won't really work for people outside the USA and 3) if you only sell fifty copies it's not a wildly silly suggestion.
"Write your email address legibly on a piece of paper and mail it with a US $1 bill to $ADDRESS."
Obviously 1) it will cost people 68¢ for a stamp, 2) won't really work for people outside the USA and 3) if you only sell fifty copies it's not a wildly silly suggestion.