Hello. I have a Zencart store where I only sell virtual products. The products should always have Free Shipping by default. How can I do this?

In other words, how can I make it so that by default, none of my products require the shipping page?

I write by default, because I add products into my store through direct database injection. I don't use the /admin panel. I still want all of the products to get the Virtual/Free shipping modifiers...

How?

Thank you very much.