How to identify a customer that is not logged in on shopify

You can use this code snippet to display different content on the site based on whether the user is logged in or not. Great for wholesale customers.

{%- if customer.id == null -%}
<div class="product-retail-link"><a href="#">Your text here</a></div>
{%- else -%}
Logged in Customer
{%- endif -%}