This is applicable to Microsoft Visual Studio.NET developed Websites and Web Application Projects. I found this to be true on both VS 2008 (.NET 3.5 Framework) and 2010 (.NET 4.0 Framework).
I honestly don’t know why this fact doesn’t get more airtime:
When publishing a website in Visual Studio USE the following setting:
“Use fixed naming and single page assemblies”
Do NOT use:
“Allow this precompiled site to be updatable”
This appears to opposite of the default settings in Microsoft Visual Studio.
This is particularly important for websites with low traffic.
When you do this, the website will respond much faster!
Explanation: The settings have to do with the pre-compilation of the assemblies used by the website. The settings are VERY, VERY CONFUSING!
- “Use fixed naming and single page assemblies” means that the entire site is compiled. This is FAST!
- “Allow the precompiled site to be updatable” means that the site will be dynamically compiled when it has been inactive for a set amount of time. The end result is that the website is VERY SLOW to respond when it is hit (especially the first time after the website has inactive for a while).
By John Dorsey IT Brigade Inc. 
ASP.NET
Microsoft, BlogEngine.NET, ASP.NET