To know where your leads are coming from before converting on your landing page, you can utilize URL parameters or UTM parameters (if you're using Google Analytics).
Add URL Parameters
If you're running a Facebook ad, you can add a URL parameter to your ad's landing page link like this:
If you'd like to track more than just the source, you can add more URL parameters by separating them with "&":
This way, if a visitor clicks through from your ad on Facebook and converts, the parameter will be read into the hidden field you have set up, then it will be submitted along with the form submission.
If you're running an AdWords ad, you can use auto-tagging or manual tagging to capture the referral data. To learn how to set up this tracking, head to the help article:
Capture URL/UTM Parameters with Unbounce
To capture this data in Unbounce, you'll need to create a hidden field in your form with the same label as the variable name. In this example, the hidden field should be named "utm_source" - this will capture the value and help you track where your referrals are coming from! To learn how to set up your form with the correct hidden fields, head to the help article: