Calling, works, and is far more effective than clicking a button, says Alexis Ohanian, in this fireside chat at the NationBuilder HQ.
Uploaded a couple of days ago: http://youtu.be/ybXKBJ0xDNU?t=10m35s
Uploaded a couple of days ago: http://youtu.be/ybXKBJ0xDNU?t=10m35s