MyPostcard.com will donate $1 to Rotary’s polio fund for every purchase made on its website with the code ENDPOLIO.

MyPostcard.com lets you customize postcards online and mails them throughout the world.

Through a generous 2-to-1 match by the Bill & Melinda Gates Foundation, each contribution will be tripled. Each purchase will fully protect at least one child from paralysis by the poliovirus — for life.

This offer lasts through 31 October.