Outsider

When it comes to designing conversion-critical processes, usability and persuasion are two concepts that often come to mind. They may be complementary, but they can also be opposing sometimes.
This is my oh-so-biased view:

Usability
Persuasion

Is the brainchild of…
engineers
advertisers

Treats the user as…
an agent: will consider her options and do what she thinks is right
a patient: her behaviour can [...]