This filter is used when displaying the “your cart is empty” message and can be used to modify the message that is displayed. The sample below shows an example of how you could modify it:

function my_custom_empty_cart_message($message) {
	return '<p class="my_empty_cart">' . $message . ' Please buy something.</p>';
add_filter('edd_empty_cart_message', 'my_custom_empty_cart_message');

This will add paragraph tags around the message, and include the words “Please buy something”.