This is information that eBay provided in the Summer Seller Update located here.
eBay is requiring zip codes as of 7/31/18. This information is required to assist buyers in having a better idea of when an item will reach them based on the shipping distance. If you have other questions regarding this change, please feel free to contact eBay directly.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .