Allow your visitors to fill out the form using their social network. You will automatically get extra data and they get a quicker experience.
Not all customers have purchased this functionality. Contact your sales rep for details.
Go to Marketing Activities.
Select your form and click Edit Form.
Under Form Settings click on Settings.
Check the social network buttons you want to include.
Take a look at what data Marketo will capture if people use the social buttons.
Click Approve and Close.
Here it is.
Pretty awesome, huh?