It's a bit strange that FastPages' definition of a Landing page is tied directly to a domain/subdomain.

So, when I create a Landing page, its URL is
http://landingpage1.fastpages.com and NOT http://fastpages.com/landingpage1

This is an important distinction because when I've configured my own domain/subdomains, there is NO way to have "Unlimited" landing pages unless you've bought 5 codes.

So, in my account, I've configured 2 Landing Pages to use my custom domains and it looks like this:
http://landingpage1.myDomain.com (this counts as 1st domain according to FastPages)
http://landingpage2.myDomain.com (this counts as 2nd domain according to FastPages)

So, 2 Landing Pages used up 2 domains, duh!! There is NO way to have "Unlimited" Landing Pages if I use my own domain because you cannot do this:
http://myDomain.com/landingpage1
http://myDomain.com/landingpage2

When using my own domains/subdomains, a Landing Page will use up 1 domain/subdomain. So if you buy 1 code, you ultimately have only 5 Landing Pages if you use your own domains/subdomains. 2 codes give you 10 Landing Pages if you use your own domains/subdomains.

@FastPages: is this by design or is this an oversight in development that will get implemented soon so we can truly get "Unlimited" landing pages to use with our own domains?