Wes,
Another option you can use is the IIS 7 URL Rewrite module 2 (http://learn.iis.net/page.aspx/460/us...) along with  your Landing Page folder in your DNN root  with asp.net page(s) in that folder.
Your page url look s like: yoursite.com/LP/JanuaryPromo and your can have a redirect (rewrite) page like this:yoursite.com/LP/index.aspx?para=JanuaryPromo
You would write your normal ASP.NET pages in this folder and use the DNN connection if you use some sort look up tables in DNN database.

An example URL rewrite rule in your web.config you can refer:

<rewrite>

<rule name="RewriteUserFriendlyURLSample" stopProcessing="true">

<match url="^LP/([^/]+)/?$" />

<conditions>

<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />

<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />

</conditions>

<action type="Rewrite" url="LP/index.aspx?para={R:1}" />

</rule>

</rules>

</rewrite>