Domain Name for Landing Pages

When creating a landing page, do you buy a domain name for each product you sell, or just add a page to an existing website you own? I’m wondering if there is any advantage to buying a new domain for each product you offer? As in when creating a sales funnel, or landing page for an affiliate product.

Are you an Inner Circle or Gold Member? Because the answer will be different based on your promotion strategy

No need to buy a new domain is enough to create a single page for each product

just a single domain should work fine