What's the difference between the Personal and Web Hosting certificate store?
from IIS.NET:
The key difference between Web Hosting store and Personal store is that Web Hosting store is designed to scale to higher numbers of certificates.
For lightweight scenarios (when you have less than 20-30 certificates) you can use any, Personal or WebHosting store.
When you have 30+ different certificates, you should use Web Hosting store for performance reasons.
addition to Sam.Rueby's Answer:
There is not a StoreName enumeration value for Web Hosting, but Web Hosting store can be accessed by using StoreName value as "WebHosting".
var store = new X509Store( "WebHosting", StoreLocation.LocalMachine);
I agree with CyptoGuy that IIS.NET states the the difference is that Web Hosting is designed to scale to more certificates. I think I found another important difference, which is that I have yet to find a way to access the Web Hosting store from .NET code. Specifically because there is not a StoreName enumeration value for Web Hosting: http://msdn.microsoft.com/query/dev12.query?appId=Dev12IDEF1&l=EN-US&k=k%28System.Security.Cryptography.X509Certificates.StoreName%29;k%28TargetFrameworkMoniker-.NETFramework