Marketing sources are a great way of seeing how the customer has found out about your club whether that be via a social media, a friend etc.
Once a marketing source is setup then when a customer signs up online they can let you know how they found out about you.
To setup marketing sources you will go to the settings in the top right.
Then click on marketing sources.
Now press 'add new source'
Enter the name of the source.
This will then be good to go.