I was talking with a friend about what IIS does when you put a new file inside a virtual directory.
He told me that IIS recompile the entire website when you put a file anywhere in the website, I think it just happens (if happen) when you put a file inside your Bins folder.
The conversation comes because a website in the company is use to upload files but the files are save inside a folder name "Letters" in our website, my friend says that every time someone upload a file IIS will recompile the entire website. Is he correct?
Easy enough to test. Start watching the JIT compile counters on the web server... Browser around, then drop a file in it to see the counters show.